Today I had a client using Outlook 2003 SP3 who was having the following symptom: When she composed a new e-mail in Outlook, she’d hit the “Send” button, and the window would turn white and block for 5-30 seconds, and then finally disappear and the program behavior would return to normal.
I tried a new Outlook profile, ensured that Outlook was up-to-date with service packs, tried turning on and off Word as e-mail editor, but nothing changed the behavior.
Eventually I tried disabling her e-mail signature, and the problem disappeared.
Well, it turned out, there were two images in her signature, company logos, that were being loaded from a couple different web servers out on the web, and depending on the day or time of day, one or both of the servers being referenced for the images were getting bogged down, and thus had high latency times downloading these <100KB images.
So every time she sent an e-mail, Outlook was going out to the web and retrieving these two images, which sometimes took up to 30 seconds to get, and then embedding the raw JPEG/GIF data into the e-mail to send it out. Of course, since the developers of Outlook apparently never imagined a case when this process would take more than an instant, Outlook blocked on these retrieval threads and locked up until the images could be retrieved (or time out, whichever came first).
The fix was disgustingly simple: Download the images manually to a local storage location (in this case, Docs share on the local SBS machine) and modify her signature to pull the images from there instead of the web location. Presto! Problem solved.