I use spacer gifs to create margins for my tables. Everything checked out in Litmus testing, but the client reporte lines where each spacer.gif was placed. She forwarded me the email and I didn't see the lines. She sent me a screenshot which was helpful. A co-worked had the same problem using Outlook 2010 on a Windows PC.

My first impression was that the spacer gifs were not included when the email was sent. But, I didn't see the problem on my Outlook for Mac. In fact, all Litmus testing passed, especially all Outlooks.

I'd be happy to hear suggestions. Thank you!