Best SMTP server for sending mass mail?
 

Is it better exim or postfix?I running cent os 6 64 bit so trying to determine before doing anything.

Both are mature MTAs. Do you (or your peers) have expertise with one or the other? Then go with that.

If you can be a lot more descriptive about your goal than "sending mass mail", someone may be able to help further. Otherwise, it's just a guessing game about available resources and the volume you have in mind.

That's the problem,only experience which i have its with sendmail :)

Actually i'l go with postfix since it's supported in webmin and exim not and seems it working pretty fine :)

Fair enough, and I see you've marked your thread as solved. I did see (and read) this -- one of the first google results for "comparison of mtas":

http://shearer.org/MTA_Comparison

Thoughtful, subjective analysis, if you're interested.

I think Postfix is a solid MTA, but I have to stick with what I said earlier. If you're already comfortable with Sendmail, I don't understand why you would switch to a new MTA for a (presumably) production project.