How to block sending mails?

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











up vote
1
down vote

favorite












I want to block specific user from sending emails. I tried doing these things which did not help:



  1. Commented user in /etc/passwd

  2. Wrote passwd -l user and restarted sendmail service.

User can't receive mails - that's OK, but they still may send mails. I use Sendmail (port 25) and Dovecot (port 110 POP3).



Any ideas to block a user from sending mails?






sendmail







share|improve this question



















  • 1




    The purported duplicate question is about a Posfix system. This question is about, as it says, a Sendmail system. It is not the same answer for both.
    – JdeBP
    Aug 8 at 10:09










  • Then it is not dupe.
    – peterh
    Aug 8 at 19:55














up vote
1
down vote

favorite












I want to block specific user from sending emails. I tried doing these things which did not help:



  1. Commented user in /etc/passwd

  2. Wrote passwd -l user and restarted sendmail service.

User can't receive mails - that's OK, but they still may send mails. I use Sendmail (port 25) and Dovecot (port 110 POP3).



Any ideas to block a user from sending mails?






sendmail







share|improve this question



















  • 1




    The purported duplicate question is about a Posfix system. This question is about, as it says, a Sendmail system. It is not the same answer for both.
    – JdeBP
    Aug 8 at 10:09










  • Then it is not dupe.
    – peterh
    Aug 8 at 19:55












up vote
1
down vote

favorite









up vote
1
down vote

favorite











I want to block specific user from sending emails. I tried doing these things which did not help:



  1. Commented user in /etc/passwd

  2. Wrote passwd -l user and restarted sendmail service.

User can't receive mails - that's OK, but they still may send mails. I use Sendmail (port 25) and Dovecot (port 110 POP3).



Any ideas to block a user from sending mails?






sendmail







share|improve this question















I want to block specific user from sending emails. I tried doing these things which did not help:



  1. Commented user in /etc/passwd

  2. Wrote passwd -l user and restarted sendmail service.

User can't receive mails - that's OK, but they still may send mails. I use Sendmail (port 25) and Dovecot (port 110 POP3).



Any ideas to block a user from sending mails?






sendmail




sendmail






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Aug 8 at 10:05









slm♦

238k65491662




238k65491662










asked Aug 8 at 9:39









it dev

244




244







  • 1




    The purported duplicate question is about a Posfix system. This question is about, as it says, a Sendmail system. It is not the same answer for both.
    – JdeBP
    Aug 8 at 10:09










  • Then it is not dupe.
    – peterh
    Aug 8 at 19:55












  • 1




    The purported duplicate question is about a Posfix system. This question is about, as it says, a Sendmail system. It is not the same answer for both.
    – JdeBP
    Aug 8 at 10:09










  • Then it is not dupe.
    – peterh
    Aug 8 at 19:55







1




1




The purported duplicate question is about a Posfix system. This question is about, as it says, a Sendmail system. It is not the same answer for both.
– JdeBP
Aug 8 at 10:09




The purported duplicate question is about a Posfix system. This question is about, as it says, a Sendmail system. It is not the same answer for both.
– JdeBP
Aug 8 at 10:09












Then it is not dupe.
– peterh
Aug 8 at 19:55




Then it is not dupe.
– peterh
Aug 8 at 19:55










1 Answer
1






active

oldest

votes

















up vote
1
down vote













In Sendmail you can add this user to the /etc/mail/access database file (access.db) to disallow them from sending emails:



Put their address in the file /etc/mail/access:



user@my-domain.com REJECT


Then rebuild it:



$ makemap hash /etc/mail/access.db < /etc/mail/access


NOTE: From what I remember you may have to put several permutations of their email address in this file to stop them. so things like user@localhost, etc.



I do not have a sendmail setup handy, but you can typically use a Makefile command that's provided in newer implementations of sendmail.



For more controlling the sending/receiving via Sendmail you can do more specific controls like this in this file:



To:a1@server.vikas.com REJECT # Reject a1 user from recieving mails
From:a1@server.vikas.com REJECT # Reject a1 user from sending mails


References



  • How to enable/disable user's access to email (sendmail)





share|improve this answer




















  • Is it necessary to rebuild it? I am a little frightened to use makemap command
    – it dev
    Aug 8 at 10:22










  • I seem to remember that restarting the sendmail service did this as well. But yeah you typically have to rebuild these files in order for sendmail to use them. BTW I just reinstalled sendmail on CentOS 7 and it does still come with a make command, so you should be able to run that if your setup has it. If you're pensive to do this, back up the whole /etc/mail dir 1st.
    – slm♦
    Aug 8 at 10:23







  • 1




    Good old sendmail...I prefered to deal with it editing .mc files...it would be interesting understanding the problem of the user, blocking users in sendmail wont prevent users/malware scripts form sending email/spam via TCP/25 if the infra-structure allows it.
    – Rui F Ribeiro
    Aug 8 at 10:48










  • @slm, may I only restart sendmail service after REJECTING user in access file? Will it help?
    – it dev
    Aug 8 at 11:13










  • @itdev - my suggestion was to try doing a restart after adding REJECT entry to see if it triggers a rebuild of access.db, but I'm 90% sure that you have to rebuild these manually using either rehash or the make command.
    – slm♦
    Aug 8 at 11:15










Your Answer







StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "106"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);

else
createEditor();

);

function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
convertImagesToLinks: false,
noModals: false,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);



);













 

draft saved


draft discarded


















StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2funix.stackexchange.com%2fquestions%2f461242%2fhow-to-block-sending-mails%23new-answer', 'question_page');

);

Post as a guest

















1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes








up vote
1
down vote













In Sendmail you can add this user to the /etc/mail/access database file (access.db) to disallow them from sending emails:



Put their address in the file /etc/mail/access:



user@my-domain.com REJECT


Then rebuild it:



$ makemap hash /etc/mail/access.db < /etc/mail/access


NOTE: From what I remember you may have to put several permutations of their email address in this file to stop them. so things like user@localhost, etc.



I do not have a sendmail setup handy, but you can typically use a Makefile command that's provided in newer implementations of sendmail.



For more controlling the sending/receiving via Sendmail you can do more specific controls like this in this file:



To:a1@server.vikas.com REJECT # Reject a1 user from recieving mails
From:a1@server.vikas.com REJECT # Reject a1 user from sending mails


References



  • How to enable/disable user's access to email (sendmail)





share|improve this answer




















  • Is it necessary to rebuild it? I am a little frightened to use makemap command
    – it dev
    Aug 8 at 10:22










  • I seem to remember that restarting the sendmail service did this as well. But yeah you typically have to rebuild these files in order for sendmail to use them. BTW I just reinstalled sendmail on CentOS 7 and it does still come with a make command, so you should be able to run that if your setup has it. If you're pensive to do this, back up the whole /etc/mail dir 1st.
    – slm♦
    Aug 8 at 10:23







  • 1




    Good old sendmail...I prefered to deal with it editing .mc files...it would be interesting understanding the problem of the user, blocking users in sendmail wont prevent users/malware scripts form sending email/spam via TCP/25 if the infra-structure allows it.
    – Rui F Ribeiro
    Aug 8 at 10:48










  • @slm, may I only restart sendmail service after REJECTING user in access file? Will it help?
    – it dev
    Aug 8 at 11:13










  • @itdev - my suggestion was to try doing a restart after adding REJECT entry to see if it triggers a rebuild of access.db, but I'm 90% sure that you have to rebuild these manually using either rehash or the make command.
    – slm♦
    Aug 8 at 11:15














up vote
1
down vote













In Sendmail you can add this user to the /etc/mail/access database file (access.db) to disallow them from sending emails:



Put their address in the file /etc/mail/access:



user@my-domain.com REJECT


Then rebuild it:



$ makemap hash /etc/mail/access.db < /etc/mail/access


NOTE: From what I remember you may have to put several permutations of their email address in this file to stop them. so things like user@localhost, etc.



I do not have a sendmail setup handy, but you can typically use a Makefile command that's provided in newer implementations of sendmail.



For more controlling the sending/receiving via Sendmail you can do more specific controls like this in this file:



To:a1@server.vikas.com REJECT # Reject a1 user from recieving mails
From:a1@server.vikas.com REJECT # Reject a1 user from sending mails


References



  • How to enable/disable user's access to email (sendmail)





share|improve this answer




















  • Is it necessary to rebuild it? I am a little frightened to use makemap command
    – it dev
    Aug 8 at 10:22










  • I seem to remember that restarting the sendmail service did this as well. But yeah you typically have to rebuild these files in order for sendmail to use them. BTW I just reinstalled sendmail on CentOS 7 and it does still come with a make command, so you should be able to run that if your setup has it. If you're pensive to do this, back up the whole /etc/mail dir 1st.
    – slm♦
    Aug 8 at 10:23







  • 1




    Good old sendmail...I prefered to deal with it editing .mc files...it would be interesting understanding the problem of the user, blocking users in sendmail wont prevent users/malware scripts form sending email/spam via TCP/25 if the infra-structure allows it.
    – Rui F Ribeiro
    Aug 8 at 10:48










  • @slm, may I only restart sendmail service after REJECTING user in access file? Will it help?
    – it dev
    Aug 8 at 11:13










  • @itdev - my suggestion was to try doing a restart after adding REJECT entry to see if it triggers a rebuild of access.db, but I'm 90% sure that you have to rebuild these manually using either rehash or the make command.
    – slm♦
    Aug 8 at 11:15












up vote
1
down vote










up vote
1
down vote









In Sendmail you can add this user to the /etc/mail/access database file (access.db) to disallow them from sending emails:



Put their address in the file /etc/mail/access:



user@my-domain.com REJECT


Then rebuild it:



$ makemap hash /etc/mail/access.db < /etc/mail/access


NOTE: From what I remember you may have to put several permutations of their email address in this file to stop them. so things like user@localhost, etc.



I do not have a sendmail setup handy, but you can typically use a Makefile command that's provided in newer implementations of sendmail.



For more controlling the sending/receiving via Sendmail you can do more specific controls like this in this file:



To:a1@server.vikas.com REJECT # Reject a1 user from recieving mails
From:a1@server.vikas.com REJECT # Reject a1 user from sending mails


References



  • How to enable/disable user's access to email (sendmail)





share|improve this answer












In Sendmail you can add this user to the /etc/mail/access database file (access.db) to disallow them from sending emails:



Put their address in the file /etc/mail/access:



user@my-domain.com REJECT


Then rebuild it:



$ makemap hash /etc/mail/access.db < /etc/mail/access


NOTE: From what I remember you may have to put several permutations of their email address in this file to stop them. so things like user@localhost, etc.



I do not have a sendmail setup handy, but you can typically use a Makefile command that's provided in newer implementations of sendmail.



For more controlling the sending/receiving via Sendmail you can do more specific controls like this in this file:



To:a1@server.vikas.com REJECT # Reject a1 user from recieving mails
From:a1@server.vikas.com REJECT # Reject a1 user from sending mails


References



  • How to enable/disable user's access to email (sendmail)






share|improve this answer












share|improve this answer



share|improve this answer










answered Aug 8 at 10:11









slm♦

238k65491662




238k65491662











  • Is it necessary to rebuild it? I am a little frightened to use makemap command
    – it dev
    Aug 8 at 10:22










  • I seem to remember that restarting the sendmail service did this as well. But yeah you typically have to rebuild these files in order for sendmail to use them. BTW I just reinstalled sendmail on CentOS 7 and it does still come with a make command, so you should be able to run that if your setup has it. If you're pensive to do this, back up the whole /etc/mail dir 1st.
    – slm♦
    Aug 8 at 10:23







  • 1




    Good old sendmail...I prefered to deal with it editing .mc files...it would be interesting understanding the problem of the user, blocking users in sendmail wont prevent users/malware scripts form sending email/spam via TCP/25 if the infra-structure allows it.
    – Rui F Ribeiro
    Aug 8 at 10:48










  • @slm, may I only restart sendmail service after REJECTING user in access file? Will it help?
    – it dev
    Aug 8 at 11:13










  • @itdev - my suggestion was to try doing a restart after adding REJECT entry to see if it triggers a rebuild of access.db, but I'm 90% sure that you have to rebuild these manually using either rehash or the make command.
    – slm♦
    Aug 8 at 11:15
















  • Is it necessary to rebuild it? I am a little frightened to use makemap command
    – it dev
    Aug 8 at 10:22










  • I seem to remember that restarting the sendmail service did this as well. But yeah you typically have to rebuild these files in order for sendmail to use them. BTW I just reinstalled sendmail on CentOS 7 and it does still come with a make command, so you should be able to run that if your setup has it. If you're pensive to do this, back up the whole /etc/mail dir 1st.
    – slm♦
    Aug 8 at 10:23







  • 1




    Good old sendmail...I prefered to deal with it editing .mc files...it would be interesting understanding the problem of the user, blocking users in sendmail wont prevent users/malware scripts form sending email/spam via TCP/25 if the infra-structure allows it.
    – Rui F Ribeiro
    Aug 8 at 10:48










  • @slm, may I only restart sendmail service after REJECTING user in access file? Will it help?
    – it dev
    Aug 8 at 11:13










  • @itdev - my suggestion was to try doing a restart after adding REJECT entry to see if it triggers a rebuild of access.db, but I'm 90% sure that you have to rebuild these manually using either rehash or the make command.
    – slm♦
    Aug 8 at 11:15















Is it necessary to rebuild it? I am a little frightened to use makemap command
– it dev
Aug 8 at 10:22




Is it necessary to rebuild it? I am a little frightened to use makemap command
– it dev
Aug 8 at 10:22












I seem to remember that restarting the sendmail service did this as well. But yeah you typically have to rebuild these files in order for sendmail to use them. BTW I just reinstalled sendmail on CentOS 7 and it does still come with a make command, so you should be able to run that if your setup has it. If you're pensive to do this, back up the whole /etc/mail dir 1st.
– slm♦
Aug 8 at 10:23





I seem to remember that restarting the sendmail service did this as well. But yeah you typically have to rebuild these files in order for sendmail to use them. BTW I just reinstalled sendmail on CentOS 7 and it does still come with a make command, so you should be able to run that if your setup has it. If you're pensive to do this, back up the whole /etc/mail dir 1st.
– slm♦
Aug 8 at 10:23





1




1




Good old sendmail...I prefered to deal with it editing .mc files...it would be interesting understanding the problem of the user, blocking users in sendmail wont prevent users/malware scripts form sending email/spam via TCP/25 if the infra-structure allows it.
– Rui F Ribeiro
Aug 8 at 10:48




Good old sendmail...I prefered to deal with it editing .mc files...it would be interesting understanding the problem of the user, blocking users in sendmail wont prevent users/malware scripts form sending email/spam via TCP/25 if the infra-structure allows it.
– Rui F Ribeiro
Aug 8 at 10:48












@slm, may I only restart sendmail service after REJECTING user in access file? Will it help?
– it dev
Aug 8 at 11:13




@slm, may I only restart sendmail service after REJECTING user in access file? Will it help?
– it dev
Aug 8 at 11:13












@itdev - my suggestion was to try doing a restart after adding REJECT entry to see if it triggers a rebuild of access.db, but I'm 90% sure that you have to rebuild these manually using either rehash or the make command.
– slm♦
Aug 8 at 11:15




@itdev - my suggestion was to try doing a restart after adding REJECT entry to see if it triggers a rebuild of access.db, but I'm 90% sure that you have to rebuild these manually using either rehash or the make command.
– slm♦
Aug 8 at 11:15

















 

draft saved


draft discarded















































 


draft saved


draft discarded














StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2funix.stackexchange.com%2fquestions%2f461242%2fhow-to-block-sending-mails%23new-answer', 'question_page');

);

Post as a guest
































































-

Popular posts from this blog

How to check contact read email or not when send email to Individual?

Image
Clash Royale CLAN TAG #URR8PPP up vote 1 down vote favorite I'm using WordPress 4.9.8, CiviCRM to 5.5.1, I usually send email to contact by Search> Find contacts View contact details Action> Send email Send email ok, Contact received mail ok like picture But status only Email sent though contact read email or not. So, can CiviCRM can change status to Email read when contact read email? wordpress email share | improve this question asked Sep 26 at 0:12 ToanLuong 49 9 add a comment  |  up vote 1 down vote favorite I'm using WordPress 4.9.8, CiviCRM to 5.5.1, I usually send email to contact by Search> Find contacts View contact details Action> Send email Send email ok, Contact received mail ok like picture But status only Email sent though contact read email or not. So, can CiviCRM can change status to Email read when contact read email? wordpress email share | improve this questi...
Read more

Displaying single band from multi-band raster using QGIS

Image
Clash Royale CLAN TAG #URR8PPP 1 How can I extract a single band from multi-band raster in QGIS? I have an remote sensed image which has 6 bands (including NDVI band), I want to display each band separately, but have no idea how to do. I have seen some questions similar here but none worked for me. The original image (has 6 bands) is: I want to display the band 6 which should be like this: But I tried gdal_translate, and couldn't get the correct result. What I have got is: qgis raster multi-band share | improve this question edited Mar 5 at 0:53 Summer asked Mar 4 at 6:42 Summer Summer 23 6 Is this any help gis.stackexchange.com/questions/220658/… ? if not gis.stackexchange.com/questions/62133/… might help. – Michael Stimson Mar 4 at 6:46 Thanks for answering but when I used gdal_translate, qgis showed that 'Error 4: Kayena.tif: No such file or directory". Would you know how to fi...
Read more

How many registers does an x86_64 CPU actually have?

Image
Clash Royale CLAN TAG #URR8PPP up vote 2 down vote favorite I am currently learning reverse engineering and am studying the flags register. I had in my mind that rflags was just another name for one of the 16 general purpose registers, for example rax or rbx . But it looks like rflags is actually an additional register. So that makes 17 registers in total... how many more could there be? I have spent at least an hour on this and found numerous different answers. The best answer so far is this, which says that there are 40 registers in total. 16 General Purpose Registers 2 Status Registers 6 Code Segment Registers 16 SSE Registers 8 FPU/MMX Registers But if I add that up, I get 48. Could anybody provide an official answer on how many registers an x86_64 CPU has (e.g. an Intel i7). Additionally, I have seen references to 'hardware' and 'architectural' registers. What are those registers and how many are there? register x86-64 share | improve this...
Read more