Server Fault Stack Exchange
Server Fault Stack Exchange

Questions tagged [postfix]

Free and open source mail transfer agent (MTA) that routes and delivers email. When asking about postfix problem, please include the relevant maillog lines and output of the following command: `postconf -n` (non-default content of main.cf) and `postconf -M` (content of master.cf)

Postfix is a mail transfer agent (MTA) that supports IPv6, DNSBL, SMTP AUTH (SASL), TLS and various database backend.

Postfix was written by Wietse Venema in 1997 and first released in December 1998 as IBM Secure Mailer.

It was designed to be highly secure and configurable, and is a drop-in replacement for , with much simpler configuration syntax.

The software was also formerly known as VMailer.

6258 questions
119
votes
5 answers

Postfix - how to retry delivery of mail in queue?

I have a backup mail server in case of a failure on the main one. In that case of failure, mails come on the backup server and stay there until the main one is back. If I wait some times, the delivery will be done automatically as soon as the main…
Nicolas
  • 1,199
  • 2
  • 7
  • 3
115
votes
1 answer

What ports to open for mail server?

I have just finished setting up a Postfix mail server on a linux (ubuntu) platform. I have it sending and receiving email and it is not an open relay. It also supports secure smtp and imap. Now this is a pretty beginner question but should I be…
radman
  • 1,621
  • 3
  • 16
  • 17
77
votes
3 answers

Automate the installation of postfix on Ubuntu

My system configuration script does an "apt-get install -y postfix". Unfortunately the script is halted when the postfix installer displays a configuration screen. Is there a method to force postfix to use the defaults during installation so that…
sutch
  • 956
  • 1
  • 7
  • 9
72
votes
4 answers

Is Postfix the same thing as Sendmail?

I have Postfix setup on my server so that I can send outgoing mail using the command-line: mail -s "Subject" address@example.com Is this using Sendmail or Postfix ? Is "Sendmail" just a software category or a distinct program ? If something is…
Xeoncross
  • 4,269
  • 12
  • 42
  • 55
66
votes
7 answers

How to correct Postfix' 'Relay Access Denied'?

This morning, in order to correct a problem with a name mismatch in the security certificate, I followed the recommended steps from How to fix mail server SSL?, but now, when attempting to send an email from a client (in this case the client is…
Noah Goodrich
  • 18,677
  • 6
  • 24
  • 16
62
votes
8 answers

How do I check the postfix queue size?

What's the postfix equivalent to sendmail -bp?
Gary Richardson
  • 1,767
  • 3
  • 19
  • 21
57
votes
5 answers

Forcing the from address when postfix relays over smtp

I'm trying to get email reports from our AWS EC2 instances. We're using Exchange Online (part of Microsoft Online Services). I've setup a user account specifically for SMTP relaying, and I've setup Postfix to meet all the requirements to relay…
John Whitlock
  • 1,037
  • 2
  • 9
  • 14
50
votes
7 answers

What are the practical differences between Maildir and Mbox?

Although I understand the basics of the two storage formats (1 file per email under Maildir vs. 1 single file per mailbox under mbox), I am wondering what the practical implications are here - Is one storage format more scalable than the other? Are…
olympe26
  • 509
  • 1
  • 4
  • 3
43
votes
2 answers

Understanding a Postfix log file entry

We have a Postfix hub and I'm trying to better understand the information in the mail.log file. I use tools like qshape, pflogsumm.pl and amavis-logwatch to summarize the log files, but I have still have questions about some of the elements of the…
KodeTitan
  • 871
  • 2
  • 9
  • 15
43
votes
6 answers

Postfix: Recipient address rejected: User unknown in local recipient table

When I try to send an email on my postfix server to an address on the same domain (for example, if the server hostname is mail.example.com and I try to send an email to test@example.com), I get the following error in the log and the email is not…
Tai Squared
  • 589
  • 1
  • 8
  • 10
41
votes
1 answer

How can I see the contents of the mail whose ID I get from mailq command?

I used mailq command and I got a line like for example: A705238B4C 603953 Wed May 23 11:09:58 apache@myserver.com So, now I'm wondering is there a way where I can "read" an actual content of the mail by its id A705238B4C
Nikola
  • 777
  • 4
  • 12
  • 21
40
votes
3 answers

Postfix: "Connection timed out" on all outbound email

I've been attempting to setup mailing lists with GNU Mailman but it's been a complete disaster with tons of road blocks. Postfix is able to receive email but not send it back out at all, I've peeked in the log and this is what I found: Mar 30…
APott
  • 511
  • 1
  • 4
  • 5
40
votes
4 answers

DKIM sign outgoing mail from any domain (with Postfix and Ubuntu)

I got DKIM setup on my mail server (postfix and ubuntu) so it signs outgoing emails. I used these instructions: https://help.ubuntu.com/community/Postfix/DKIM However, I need it to sign emails from any domain (in the From address) and not just my…
Brian Armstrong
  • 1,557
  • 3
  • 18
  • 22
40
votes
8 answers

Why Does hotmail still reject my emails?

I have a very strange problem with my emails being marked as spam by hotmail. I just have configured Postfix + Dovecot on my server and all works perfectly. I can Send/Receive emails. I only have problems with hotmail accounts, I do not understand…
Dail
  • 649
  • 1
  • 10
  • 13
39
votes
5 answers

"No worthy mechs found" when trying to relay email to Gmail using Postfix

I've been trying to configure email to forward to Gmail, using Postfix to relay email to smtp.gmail.com. However, I'm failing to get it to authenticate with smtp.gmail.com, which is a rather vital prerequisite to getting anything working… The mail…
gsnedders
  • 1,071
  • 1
  • 8
  • 8
1
2 3
…
99 100