New sendmail breaks ability to mail to *@mmode.com

[Jason Edgecombe]

Hmmm,

sounds like greylisting. See http://projects.puremagic.com/greylisting/

David M. Shirley wrote:
> Thanks.
>
> This gets stranger by the minute.  The folks at mmode.com SWEAR they 
> have made no changes to their sms gateway system and yet tonight:
>
> I rolled back to a prior version of sendmail and found that messages 
> sent from old (pre-upgrade) sendmail equipped servers are now also 
> being dropped THE FIRST TIME by mmode.com.  If you immediately send it 
> again, the second message sails right through to my phone.
>
> I get the same behavior from old sendmail equipped servers that were 
> functioning fine earlier today and have never been upgraded.
>
> I took a server that:
> can't get any messages through to mmode.com with the new sendmail
> and has it's first message to mmode.com lost using the old sendmail
> switched to using postfix and all messages now sail right through each 
> and every time.
>
> In all three cases, the mmode.com server accepts the messages for 
> delivery in exactly the same way as I have reported earlier in this 
> thread.
>
> It's pretty clear now that this is purely an mmode.com problem but 
> they seem unable to locate anything.  If anyone has some insight, I'd 
> love to be able to tell them, "Hey did you check this...?"
>
> This bit about always losing the first message sounds a bit like a 
> botched attempt at greylisting but I don't understand how it only 
> occurs with connections from sendmail mtas and not others like qmail, 
> postfix and exim.... Indeed messages from any of these other mtas are 
> accepted my mmode.com the first time, every time.
>
> David Shirley
> http://www.webquarry.com