Here's Kelly's question:

I have a sales rep that is using Outlook 2003 as his email client. He uses Qwest as his email domain. When he tries to send an email (without attachments) to anyone to any domain, the email goes through fine.

When he sends an email with attachment (less than 10 MB) to any person at one particular domain, the email does not go through. He looks at his sent items in Outlook and it appears the email has gone through. He receives no bounce back indicating that the email is undeliverable. .QUOTE We have tested him sending the email with attachment to 7 different domains and each receiver got the email. Any suggestions?

Attachments are often problematic. Many attachments carry virus or malware payloads, and we actively recommend our readers never, ever open attachments.

Many IT managers are aware of this and block attachments as they come into their servers. What they'll do is set up a server-based filter that looks at each message and if the message has an attachment, they'll just filter it out.

Most implementations of this sort of filtering won't send a response, because that response would often go back to a spammer or other sender of malware.

If you have a recipient who can't get attachments, the best thing to do is put the item you want to send up onto a server. Here at ZATZ, we have a special server dedicated exclusively for distributing files to specific individuals and bypassing attachments.

If you don't want to set up your own server, there are a lot of other resources you can use. This, by the way, is one reason SharePoint is so popular. You can set up shared resource zones where you can upload files for others to download.

There's a site called WhaleMail (now part of Symantec) that allows you to upload files and then send links to your associates to later download them. Another service is YouSendIt, which accomplishes the same idea.

David Gewirtz is the author of How To Save Jobs and Where Have All The Emails Gone? For more than 20 years, he has analyzed current, historical, and emerging issues relating to technology, competitiveness, and policy. David is the Editor-in-Chief of the ZATZ magazines, is the Cyberterrorism Advisor for the International Association for Counterterrorism and Security Professionals, and is a member of the instructional faculty at the University of California, Berkeley extension. He can be reached at david@zatz.com and you can follow him at http://www.twitter.com/DavidGewirtz.