How to enable port 587 (submission) in postfix

Postfix Port 587

Some internet access providers have port 25 disabled in their routers to prevent spam. If you run your own email server in a data center, you might have to enable the submission port (587) in postfix to be able to send emails from your local email client to your own mail server. Enable Submission Port ... Read more

Manage the Postfix mail queue with postsuper, postqueue and mailq commands

Manage Postfix Mail Queue

Postfix provides several shell programs to manage the mail queue. These are: postsuper postqueue mailq In this tutorial, I will show you how to use these commands to manage the Postfix mail queue. Here are examples for common tasks: List all messages that are in the mail queue postqueue -p The output looks like this: ... Read more

[Solved] Postfix: “queue file write error”

Postfix: Queue File Write Error

If you get an error like: Apr 15 12:41:03 webb4 postfix/sendmail[11234]: fatal: web1_user(12967): queue file write error in your mail log, then the value for message_size_limit in postfix main.cf is too low. Solve Postfix queue file write error Edit postfix main.cf: nano /etc/postfix/main.cf and set the message size limit to a higher value. E.g. message_size_limit ... Read more

How to Backup/Clear/Restore a SpamAssassin Bayes Database

SpamAssassin Bayes Database

Sometimes you might have to work with the Spamassin Bayes Token database. This is the database that is used by the SpamAssassin Self Learning (Bayesian) Classifier to store the ham and spam tokens. This tutorial will show you how to make a backup of that database. E.g. when you want to move it to a ... Read more

Solution for: fatal: open database /var/lib/postfix/smtpd_scache.db: File exists

If your mail server stops working (neither incoming nor outgoing email works) and you find the following error message in the mail.log file: fatal: open database /var/lib/postfix/smtpd_scache.db: File exists then the smtpd_scache.db might got corrupted. Postfix will recreate this file if it does not exist. So it can be removed to solve the issue: /etc/init.d/postfix ... Read more

Solution for amavisd error – TROUBLE in process_request: Error writing a SMTP response to the socket: Broken pipe – on OpenVZ server

If you get error messages from amavisd similar to the one posted below on a server which is virtualized with OpenVZ: Mar  5 09:09:02 v100 amavis[17378]: (17378-14) (!!)TROUBLE in process_request: Error writing a SMTP response to the socket: Broken pipe at (eval 100) line 987, <GEN44> line 31. then the issue can be caused by ... Read more

Setting up email routing to gmail / google apps via ISPConfig 3

The following guide describes the steps to add DNS records that route emails from a domain managed in ISPConfig 3 to google apps / gmail. The guide assumes that you have already setup the dns zone for your domain in ispconfig. Login to ISPConfig, click on the DNS module icon in the upper navigation bar, ... Read more

Enhanced e-mail SPAM protection in ISPConfig 3

The command below enables a stricter SPAM handling for postfix on ISPConfig 3 servers. In Detail: Reject sender hostnames with invalid syntax Reject sender hostnames that are no fully qualified domains (e.g. reject "server1" but allow server1.domain.tld) Reject sender domains that have no DNS records Check sender IP addresses against realtime blacklists. First make a ... Read more

How to change the welcome email message text in ISPConfig 3

As of ISPConfig 3.0.4, the text of the welcome email message that is sent to new email accounts is stored in the folder /usr/local/ispconfig/server/conf/mail/. The message has this format: ------------------------------------------------------------------------ From: ISPConfig <[email protected]> Subject: Welcome to your new email account. Welcome to your new email account. Your webmaster. ------------------------------------------------------------------------ The first line starts with "From: ... Read more