Win 8.1. / Live mail and Thunderbird.

When I try to email a PDF it will not complete and times out in both of the above programs. The file size is less than 1mb. I can send images and word files.

However, this does not happen every time, just when I need it not to happen. Been trying to solve this for a week,

Also had issue with Internet explorer not loading pages and timing out. Solved that by disabling protected mode.

Would appreciate some help.