SMTP Reply Codes Code Meaning 200 (nonstandard success response, see rfc876) 211 System status, or system help reply 214 Help message 220 <domain> Service ready 221 <domain> Service closing transmission channel 250 Requested mail action okay, completed 251 User not local; will forward to <forward-path> 354 Start mail input; end with <CRLF>.<CRLF> 421 <domain> Service [...]

Even if you are not specified a message size limit in your main.cf configuration file, postfix server has a default size limit. By using following command you can see the current limit. kok@postaci:/etc/postfix$ postconf | grep message_size_limit message_size_limit = 10240000 You can add (or modify if you already defined it) message_size_limit parameter to your main.cf [...]

There is a special feature supported by Spamassassin named the GTUBE (Global Test for Unsolicited Bulk Email). It consists of a rule which recognizes the 68-bytes string which is sent in the email’s body. If the email goes through spamassassin, it will be detected as spam. To test, send an email to a specific address, [...]

Recently I have installed a mail server with the ClamAV (free anti-virus toolkit for UNIX). It is easy to test if the mail server is working. We can test it by sending and receiving emails. But what about the viruses? How can I test if the ClamAV is working properly? How can check if it [...]

If you provider blocks SMTP 25 port you can use the submission port. Plesk 8 comes with a submission service definition. You don’t need to define a new service. You only need to check the “Enable the Message Submission” option , on the Plesk page Server > Mail > Preferences. tools

For my current Ruby on Rails project I am using email based authentication plug-in clearance. After the registration users get an email with an activation link, but at development environment I don’t have fully functional mail server. I don’t need it either. I just want to catch the generated emails and I don’t want to [...]

I am working on a KVM based virtualized environment.  All my virtual machines are sitting behind a virtual firewall appliance. Here comes the challenge. I need to identify and open up required ports for each individual appliance. What are the ports a mailserver would need? Here is the list of ports you need to open [...]