attachment name changes from 'ATT00283.txt' to 'ATT00100.txt' when email is downloaded to a different computer

rberke used Ask the Experts™
Outlook can be really weird sometimes.

Our company leaves downloaded emails on the ISP server for 5 days.

Two different computers download the emails, so the East Coast and the West Coast computers should both get the same emails.

I recently noticed occurances where the the names are different, like 'ATT00283.txt' and the East Coast and 'ATT00100.txt' on the West Coast. So far, the affected attachments have always been a confidentiality notice, but I don't think this will always be the case.

The ***** seems to be some sort of random number that outlook generates during download.  

This causes a problem because I have a vba program that loops through the attachment names and generates a unique hash code.  The hash code is supposed to be the same on both computers, but the random number keeps that from happening.

As a workaround, I could delete the 5 digit attachment number when calculating the hash code, so both attachments would be identical like "ATT.txt". But, that is not a totally reliable solution for reasons that ar too subtle to explain.

I would prefer to replace the 5 digits with something uniquely related to content of the attachment. In other words, if Two messages have .  For instance, I could save the .txt file to c:\...temp\then grab the first word from the text file.  But, that seems like a lot of overhead.

So, then I thought that the MAPIOBJECT might contain the size of the attachment. But, the MAPIOBJECT hides all of its properties, so I'm stuck.  

Any ideas?
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What application is creating these emails? Seems that is where to start.


I'm probably going to give up on this problem because it is unlikely it will ever be resolved.

Here a few random facts I have gathered.

I googled for att00001.txt and discovered that some apple users complain that their outgoing messages get turned to att00001.txt, but nobody mentioned anything about random numbers.

We have one associate with an Iphone whose every message contains 2 or 3 Attxxxxx.txt  attachements.  Sure enough, those attachments get different names on different computers.  In fact, if repeat the download a second time on my computer I get different attachments.

In the last 5 years I got 1000 of these messages.

About 200 contain internet headers in text format.

Another 600 have subject associated with forwards, replies, delivery failure notifications, or anti virus scan messages, but only rarely does the body actually have a normal email body.  They are usually very small files with control messages, signatures etc.  May 50 of the files were totally blank

Here is a sampling:
The following section of this message contains a file attachment
prepared for transmission using the Internet MIME message format.
If you are using Pegasus Mail, or any other MIME-compliant system,
you should be able to save it or view it from within your mailer.
If you cannot, please ask your system administrator for assistance.
[Attachment stripped: Original attachment type: "application/pdf", name: "xxxxxx, please find these 7 invoices 6300000594.PDF"]
Reporting-MTA: dns;

Final-Recipient: rfc822;
Diagnostic-Code: smtp; 550 Verification failed for <>
550-Sent:     RCPT TO:<>
550-Response: 554 Transaction Failed Unsigned DSN for [spoofed?] message not originating here.
550 Sender verify failed
Remote-MTA: dns;
Action: failed
Status: 5.0.0
this E-mail and any of its attachments may contain Time Warner
Cable proprietary information, which is privileged, confidential,
or subject to copyright belonging to Time Warner Cable. This E-mail
is intended  ......etc etc
I am closing this by answering my own question.  

In my particular application, I need a unique number that can match the East Coast computer email to the West Coast computer email.

Ideally, my hash code was supposed to be md5hashsum(all attachment names + subject + body + from + to + cc)

The hash code did not match because the att*****.txt emails had different names at the two computers.

I resolved my problem by changing it to be md5hashsum( count(all att*****.txt) + all  other attachment names + subject + body + from + to + cc)

This is slightly undesirable because it treats every att*****.txt as if it had the exact same contents, and theoretically that will not always be the case.   In other words, I might get matching hash code even though two messages are slightly different.

But the odds of ever receiving two emails at the same time  with thes same body with slightly different attachments are very very very small so I am quite confident my solution will work.


I have also noticed similar problems with the following other types of attachments.  Again random numbers from the same email.

There maybe others


But, I have not been able to confirm random numbers for the following  -- these seem to be normal attachments.

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