[CentOS] Sendmail failing on home machine

Christopher Chan christopher at ias.com.hk
Wed Nov 7 08:08:27 UTC 2007

John R Pierce wrote:
> Christopher Chan wrote:
>>> configure your sendmail to use your ISP's mail server as a 'smarthost'.
>> How is that going to help the dest mta verify his address?
> it won't have to.      his ISP will accept mail from its own customer's 
> IP address, same as if they were end user mail clients, and it will 
> relay for him.   the destination MTA will presumably accept mail from 
> his ISP's mail server, unless they are a known spammer.

The dest mta is most probably doing a blank sender address verify on all 
emails. Although running a mail server on a dynamic ip is discouraged 
and use of the ISP's relay box is encouraged, I doubt that in this case 
that it will make any difference unless the dest mta has the ISP's ip(s) 
whitelisted which I doubt every much. The solution is to use a 
verifiable returnpath with bonus points for setting DS.

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