Using your previous tip, I’ve removed some unneeded text from a message that I received (a long signature and some old replies). However, I’ve noticed that now the message actually is larger. I was expecting it to be smaller since I’ve only removed text and not added any.
How is this possible and how can I prevent this?
This issue happens because when you edit a message, some style definitions of the default editing template and message specific settings are loaded into the message itself.
Normally, this is not a problem because Outlook filters out these style definitions which haven’t been used when sending. However, when you edit a message and save the changes, this filtering does not happen and the message gets saved with all the definitions and additional settings; used or not. This could add about 15 – 25KB to a single message.
There is no real way to prevent this and the impact is relatively small if you edited the message to improve readability. If you really want to decrease the message size as much as possible, you’ll have to convert the message to Plain Text.