Resolving “mail loops back to self” issues with Sendmail

If you are getting local email (to local users, eg root) bounced back with errors stating ‘mail loops back to self’, ensure that the hostname and domainname map to localhost and localdomain respectively:

<code>
hostname localhost
domainname localdomain
</code>

If you set these to be a hostname or domainname that you have for your MX DNS entry, this seems to give the error ‘mail loops back to self’

Microsoft seeks suggestions from Linux Users

Always eager to capture every possible aspect of the market they already dominate, Microsoft has been posting user surveys to individual Linux users and Linux User Groups soliciting feedback on how Microsoft can improve Windows.

If imitation is the best form of flattery then I guess this is the strongest acknowledgement from Microsoft you will see that Microsoft accepts that Linux does have advantages over Windows. Microsoft is obviously worried that it may lose market share (if it is not already) to Linux if it can’t add/support similar features that Linux already has (how about security, reliability, and price for starters?)

If you can’t beat ’em, join ’em, hey Bill? 🙂

Sendmail Configuration Basics

Sendmail configuration should be done in the /etc/mail/sendmail.mc file

To generate configuration changes, use the m4 macro processor:

<code>
m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf
</code>

To restart sendmail after making changes:

<code>
/etc/init.d/sendmail restart
</code>

Define the domainnames for which your mail server handles mail for in the /etc/mail/local-host-names file. For example, if you handle mail for example-abc.com, add this to the local-host-names file.
Restart sendmail after you make changes to this file.