Missing emails with certain attachments

[Sam Robins]

Hello,
We're running Windows Server 2003 SP2 and using built-in IIS SMTP and POP3
Service to relay emails.

One of our customers has Windows 2000 SP4 with Outlook 2003 SP1 and he
experiences a weird problem when he sends out emails with attachments to our
server.
1) emails with no attachment come through ok
2) emails with TXT attachments come through ok
3) emails with ZIP attachments come through ok
4) emails with PDF attachments come through ok
5) emails with PNG attachments will not be received by our POP3 Service
6) emails with GIF attachments will not be received by our POP3 Service
7) emails with JPG attachments will not be received by our POP3 Service

So there is no error whatsoever and POP3 Service will just ignore the emails
completely!

There is more:

a) If customer requests a delivery receipt he gets notification that the
email was delivered and relayed successfully.
b) The customer claims he is able to send all kinds of attachments to anyone
except us and never had any problem with his emails missing or being
undelivered with other servers.

I don’t understand who’s problem is this; his with Outlook or our with
built-in POP3 Service (although we are able to receive all kinds of
attachments from everyone else).

I hope someone would be able to help…
Thanks!

 

[Oliver Vukovics]

Hi Sam,

maybe you attachments will be blocked.

"How to configure Outlook to block additional attachment file name
extensions"
http://support.microsoft.com/kb/837388/en-us
http://www.slipstick.com/outlook/esecup/blockzips.htm

also this tool could be helpfull to unblock" your files:
http://www.howto-outlook.com/products/outlooktools.htm

Maybe it helps.

 

[Sam Robins]

Nope, there are no blocked attachments. As I mentioned earlier "The customer
claims he is able to send all kinds of attachments to anyone except us". And
we do not get the email at all (even if attachments were blocked we would
still get the message but we don't).
=======================================

 

[Oliver Vukovics]

Hi Sam,

sorry for delay, but I did not find any further information about this
behavior in Outlook.

Sorry.