Using GMail as SMTP Client

I have had some problems recently adding another email account that I own to my gmail account as a ‘send as’ account. I have the option of using GMail SMTP servers but it adds the annoying ‘Sent on behalf of…” to the messages and I already have a postfix server setup for this account.

I would try everything offered. TLS, SSL, Unsecured, All different ports that I know I had open and working for years. I kept getting this error:

Your other email provider is responding too slowly. Please try again later, or contact the administrator of your other domain for further information.

Which is complete crap because I’m tailing the postfix log file and it never even hit me.

Well, as a test instead of giving GMail the DNS hostname of my postfix server I gave it the direct IP address and it just worked instantly. It seems the error is related to DNS. Not sure why, everything works great elsewhere.

Working for me now. Hope it helps somebody else.

By |July 18th, 2013|Categories: General|Tags: , , |5 Comments

How to Setup Postfix

I sold the PowerEdge 2950 server tonight, been trying for a while. Hope you enjoy the server as much as I did man!

But he asked a question that I’m sure a few other people could use a little help on.

I have Postfix installed but how can I get it to really be a mail server for a domain?

Well this is actually not all that hard, but does require some setup in DNS.

First you need to login to which ever control panel you use for your domain name record management. (If you run your own BIND server I doubt you need this help anyway.) Check to make sure you have an `A` record that your domain name points to an IP address of the server (or public IP of router to route inside a network) something like ” `` POINTS TO “.

Second we need to make a `MX` record with the same name as the domain name for which you want after your @ address. So email `` this would just be ``. The value of the `MX` record will be the same hostname of the `A` record you created before.

Third for just this testing purposes the `priority` of the `MX` record value can be say `20`.

Save your changes and let the DNS records get updated to all the servers (this could take up to 10 days for really old, slow out of the way DNS servers).

You should be able to telnet to the A record on port 25 and get your mail server as long as it’s running and the ports are mapped if you use a NAT type setup. This tells us our A record is working.

You can then run any of the online SMTP online tools to test your DNS and SMTP servers setup to make sure things actually are reaching your server.

Please remember that hosting a mail server on a dynamic + public, provided IP address from most ISP’s in the US will usually get caught as spam.

By |March 1st, 2013|Categories: How To|Tags: ,