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)

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94
votes
4answers
268k views

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 ...
85
votes
1answer
131k views

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 ...
65
votes
2answers
27k views

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 ...
59
votes
3answers
86k views

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 ...
54
votes
8answers
120k views

How do I check the postfix queue size?

What's the postfix equivalent to sendmail -bp?
54
votes
6answers
369k views

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 ...
40
votes
4answers
29k views

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 ...
38
votes
8answers
30k views

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 ...
38
votes
5answers
30k views

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 ...
35
votes
2answers
34k views

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 ...
33
votes
2answers
5k views

Sending malicious email as a test

I have set up a working SMTP relay together with MailScanner. This SMTP relay is not — and will not be — able to relay email from the outside, only local email. Is it possible to send a ...
32
votes
1answer
45k views

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 ...
28
votes
4answers
111k views

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 ...
28
votes
5answers
44k views

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 ...
28
votes
1answer
9k views

Postfix TLS over SMTP - RCPT TO prompts renegotiation then 554 5.5.1 Error: no valid recipients

I've setup ispconfig3 on my debian six server, and here is a little smtp over ssl: The server is postfix AUTH PLAIN (LOL!) 235 2.7.0 Authentication successful MAIL FROM: lol@lol.com 250 2.1.0 Ok ...
27
votes
4answers
24k views

“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 ...
27
votes
7answers
48k views

postfix - how do you redirect all emails to one user, eg *@example.com → user@example.com

I'm using postfix for my email. I know I can use /etc/aliases and newaliases command to redirect certain email, eg I can redirect root@example.com to user@example.com by putting root: user in my /etc/...
26
votes
2answers
27k views

Can postfix be set up to forward mail to multiple recipients

I have the following postfix virtual file: test@domain.com bob@me.com This correctly forwards all emails to test@domain.com to bob@me.com However I would like to forward these emails to bob2@me....
24
votes
3answers
25k views

How to redirect all postfix emails to one external email address?

To create a test email server, I have a similar requirement as: How to redirect all outgoing email from postfix to a single address for testing But I need to send all the emails to an external ...
24
votes
4answers
39k views

How to configure postfix to pipe all incoming email to a script?

Using postfix, I'd like all incoming mail, to any address (including those that don't map to local users) to be piped to a script. I've tried configuring mailbox_command in /etc/postfix/main.cf: ...
23
votes
4answers
115k views

Fixing My MTA's Poor Reputation

I have a web site that needs to send email to customers to deliver files that they have purchased. Reliable email delivery is vital to this business. Unfortunately, most of the emails sent by my ...
22
votes
2answers
3k views

Is an IPv6-only MTA possible yet?

Has anyone had tried to run an IPv6-only SMTP engine? Pretty much everybody with any sense has IPv6 configured for major front-end servers. I was curious if anyone had tried to run an IPv6-only MTA ...
22
votes
2answers
20k views

Confused about alias_maps and virtual_alias_maps

I have already re-read the docs on this as well as other posts here and this is still very unclear to me. I have been testing various things to understand the difference between alias_maps and ...
22
votes
3answers
55k views

Forcing encryption for outgoing SMTP with Postfix

Does anyone know how to tell Postfix to encrypt outgoing mail? I have configured it to use encryption on reception, but I'm unable to do it with the outgoing mail. This is my main.cf file: ...
22
votes
3answers
59k views

POSTFIX fatal: no SASL authentication mechanisms

I am struggling with the error above for more than 5 hours. I had tried to remove Postfix completely and I had followed the instructions of the next manual and the SASL manual in order to reinstall it....
22
votes
3answers
88k views

Postfix - Host or domain not found

I've just installed Postfix on my Ubuntu, on a local network. On this network, I have an Exchange Server (using domain mail.example.com). I had a problem sending an email to a local address: adress@...
22
votes
3answers
97k views

Postfix: “Connection timed out” on all outbound email [closed]

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 ...
21
votes
4answers
44k views

How to make Postfix use another IP address?

I'm using the Postfix mail server and I have 6 IPs available. I'd like to use another IP for the Postfix mail server for sending mail than the web server uses. How can I do this? My postfix version ...
20
votes
5answers
1k views

Is it good practice or too draconian to reject mails from mailservers with no RDNS

I've recently dropped SpamAssassin and am now basing spam rejection on DNSRBL's, grey-listing and other basic tests and I'm wondering whether I should also block hosts that don't have a valid RDNS ...
20
votes
2answers
18k views

Virtual Domains with Postfix and SSL

I've got a Postfix mail server setup for hosting multiple virtual domains (say xxx.com and yyy.com). Users configure their outgoing mail server as mail.xxx.com and mail.yyy.com. All mail servers ...
20
votes
2answers
43k views

SASL LOGIN authentication failed: UGFzc3dvcmQ6 - Find the username

First let me state that the mail server is working fine and users can connect and send email. Basically there is a local web script connecting into the mail server trying to send mail every few ...
19
votes
4answers
55k views

Changing the maximum mail size in Postfix

When sending large email to a new CentOS6 server running Postfix as the MTA, the following message is returned: tried to deliver your message, but it was rejected by the recipient domain. We ...
19
votes
3answers
26k views

How should I test Clam Anti-Virus?

I have setup a new email server and now I need to test that Clam Antivirus is scanning messages correctly. How should I do this in a safe and controlled way?
19
votes
1answer
20k views

How read mail from /var/spool/postfix/deferred?

Is there a way to read deffered mail from /var/spool/postfix/deferred. I tried to copy file to my mail directory and see it from webmail but it dosnt work. When im using less or cat it seems like ...
18
votes
7answers
10k views

Can't change OpenDKIM socket in Debian stretch in /etc/default/opendkim

I am trying to set up opendkim on Debian stretch but I fail at changing the socket. I want to change the socket to /var/spool/postfix/opendkim/opendkim.sock so I can use it with postfix. I have added ...
18
votes
4answers
22k views

Send mail from Docker container with host's Postfix

I am running an Ubuntu 14.04 (Linux) server. I have installed and configured Postfix and OpenDKIM very nicely on the server; I can send emails to myself with commands such as echo hi | sendmail root, ...
18
votes
1answer
23k views

Configure Postfix to only allow outgoing mail from localhost

How do I configure the Postfix mail submission agent to only allow emails to be sent out from a user on localhost , but allow the Postfix mail transfer agent to receive mail from anywhere?
18
votes
6answers
20k views

Postfix aliases and duplicate e-mails, how to fix?

I have aliases set up in postfix, such as the following: all@mydomain.com: foo@mydomain.com, bar@mydomain.com ... When an email is sent to all@mydomain.com, and any of the recipients in that ...
17
votes
1answer
20k views

How can I configure Postfix to retain copies of all email sent through it?

My company currently uses Google Apps for email. I can configure Google Apps to forward all outgoing email through a relay server. I can also point my MX records at this server and have it forward ...
17
votes
7answers
14k views

Fail2Ban: already banned?

I have Fail2Ban running on my Centos Server. (Config below) In my var/log/messages I noticed something really weird: Jun 19 12:09:32 localhost fail2ban.actions: INFO [postfix] 114.43.245.205 ...
16
votes
1answer
18k views

What's the difference between postfix/smtp and postfix/smtpd

A bit confused when reading through the logs of my smtp/mail server, I'm turning this questions to you guys. In the maillog files I'm seeing entries for postfix/smtp as well as postfix/smtpd. I can ...
15
votes
4answers
23k views

Is there any way to see if the mail sent by my server was received by the recipient server?

I've sent an important email that the recipient claims it wasn't received by them. They say that they asked their IT team to see if the email was received in their server. According to them the email ...
15
votes
4answers
28k views

Postfix disable local delivery

Is there any form to prevent local delivery on a postfix server? Ideally, I want to avoid local delivery to some domains, because this postfix server is a google apps backup one.
15
votes
3answers
31k views

How to collect bounces in postfix

This is related to this question: linux - Ways to get a bounceback report for my newsletter application? - Server Fault Let's say I'm generating email addresses like this when I send out ...
15
votes
2answers
14k views

Can't receive mails from Gmail

A few days ago Gmail suddenly decided to stop sending mails to my mailserver. I am using Postfix and Dovecot with an paid SSL Certificate running on Debian 7 with everything updated. My mail.log ...
15
votes
2answers
57k views

How do I configure PostFix to allow other machines to send out email through it?

I have PostFix up and running on a CentOS box and would like to send mail from a Windows server on the same network out through the PostFix server. When I try to telnet from the Windows server into ...
15
votes
3answers
13k views

Remove/hide client sender ip from postfix?

I'm trying to hide the client IP from emails sent from postfix. here is an example of what I mean: Received: from mail.[removed].com (adsl-75-37-61-254.dsl.frs2ca.sbcglobal.net [75.37.61.254]) (...
15
votes
4answers
13k views

SRS / Sender Rewriting when forwarding mail through postfix

Is there any way to perform SRS, or something similar using Postfix? When I get a mail from user@example.org, I forward it (via a catchall) to something@gmail.com, but GMail is checking SPF, and ...
14
votes
6answers
1k views

How do you monitor a monitoring server?

So we run Groundworks (with Nagios) on CentOS to monitor our various servers and processes. I have it setup to automatically send emails and SMS texts when things reach a WARNING or CRITICAL state. ...
14
votes
2answers
20k views

How can I query postfix to test is an address is in the virtual address file?

Is there something I can run from the command line that will let me query postfix (running locally)? if an address is in the virtual address file and, where the mail for that address is routed to. ...