Hey Randy,

Sorry to be absent for so long! My dad was diagnosed with cancer about the time you posted this message and it's been a lot of work helping him and mom take care of some things (including him!).

He underwent a bone biopsy surgery yesterday (his first time in a hospital at that) and we found out that instead of a bone cancer sarcoma, his femur is being deteriorated by lymphoma cancer which ends up being good news! Lymphoma is treated easily with chemo and the bone will heal as opposed to having to be cut out if it were just bone cancer. So, we are all releaved that what would have been a year and a half of drama may turn out to be only 6 to 8 months!

As for the topic you posted on, this is an issue which involves Yahoo! and not any of our mail servers. BTW, I'm now involved in IceWarp support as Deerfield has dropped the branded version of IceWarp (Visnetic Mail Server) and is now reselling Ice Warp itself. So I'll be digging into IceWarp deeply over the next month or so.

I have several open tickets with Yahoo! for myself and some of my customers over these types of delivery problems to Yahoo mail accounts. Of the few responses I've received back from them, little information is shared with the exception that they state changes to their mail system are to prevent SPAMmers from getting to their Yahoo! mail account holders.

I've experienced this issue with customers using VMS, IceWarp, SendMail, etc. so it does not seem to be a problem with the mail server. I even went as far as to suggest that people not use Yahoo! mail any longer in some cases.

One thing I've learned is that Yahoo! claims to not be using any sort of GreyListing. However, there is some sort of deferral going on as can be seen by the logs. The communication between the mail server and the Yahoo! servers shows 421 response codes when connecting to Yahoo! mail servers for mail delivery. You might see something like this:

203.188.197.10  [0EE4] 14:08:18 Client session << 421 4.7.0 [TS01] Messages from nnn.nnn.nnn.nnn temporarily deferred due to user complaints - 4.16.55.1; see http://postmaster.yahoo.com/421-ts01.html

From what I've been told by Yahoo!, this means that a message which was received once and deferred never tried again after 10 mins. If that isn't some sort of deferral system, I don't know how you could define one.

So to prevent this as much as possible, check a couple of settings in the "SMTP Service/Undeliverable Messages" in IceWarp to see that you are really attempting to resend mails on a reasonable schedule (not sure exactly where the settings are yet as I've not found all of them in IceWarp):

1. Undeliverable after: Should be set to 4 days.
   
2. Warning After: Should be set to 8 days.
   

That might help a little. If you want some more information on what Yahoo! says the response codes mean, see http://postmaster.yahoo.com/421-ts01.html.

Hope this helps a little,

Marty

Hi Marty, et al,

Any Merak (now IceWarp) admins still listening here? Recently we've been having trouble delivering any messages to known-good Yahooo addresses. Bouncebacks look like this:
<code>
Reporting-MTA: DNS; mail.cycla.com
Arrival-Date: Wed, 17 Jun 2009 14:00:50 -0400

Original-Recipient: RFC822; <rick_somebody@yahoo.com>
Final-Recipient: RFC822; <rick_somebody@yahoo.com>
Action: failed
Remote-MTA: DNS; e.mx.mail.yahoo.com
Last-Attempt-Date: Wed, 17 Jun 2009 18:01:44 -0400

Does this look like something we can affect at our end?

TIA,

-- Randy

Custom Softworks

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