Postfix : lessons learnt

How to check mail queue:
mailq

How to delete all mails in queue:
postsuper -d ALL

where to see mail logs:
/var/log/mail.log


How to enable google to authenticate email address:

• Go to the Admin Console
• Click on "Google Apps"
• Click on "Gmail"
• Scroll down until you see "Authenticate Email" and click that
• Select the domain you wish to add DKIM to
• When it asks what prefix you want to use, simply use the default of 'google'

You will then see a TXT record in two parts, one piece has the domain and the other has the actual TXT record. You need to go into your DNS settings on your server for your domain and add this record. If your DNS control panel does not allow you to add the domain of google._domainkey, simply make the domain fully qualified like google._domainkey.onlinetyari.com