Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

My ISP imposes SMTP restrictions on outgoing mail, is it possible to configure a system wide SMTP address to use, instead of having to configure each mail client individually?

share|improve this question
I having problems with the mail command. How were you able to tell it was an isp block? – naftalimich Aug 1 '12 at 1:47

This worked for me:

  • Open up /etc/postfix/
  • Replace relayhost = by relayhost = where is your ISP's SMTP server.
share|improve this answer
That'll work if postfix is your installed MTA, yes. – Shadur Mar 26 '14 at 11:33

Most of the commonly used MTAs in linux distributions can be configured to send all outgoing mail via a so called 'smarthost'.

In the case of postfix, that's via the relayhost option as described in @OlivierLalonde's answer; however, every mail server has its own way of configuring things, and until and unless you specify which one you're using it's hard to help you further than this.

You can try telnet localhost 25 and look at the greeting string, that should normally tell you what program's doing the answering.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.