Agreed I do get some .mp4s as well, so .avi, .mkv, and .mp4 are probably the most common containers.
And. like Ace, I also use
K-Lite (Standard) to supply my codec needs or there is also
CCCP as and alternative. With either of these (do not install both) you should be able to play .mov files as well as all other common codecs.
Still, in order to make the files smaller I would try some conversion or re-rendering program to make files you can email to friends (typically you should keep the files under 10Mb and some mail systems may even require attachments of only 1 or 2Mb). And I would use a common container like .avi or .mp4 rather than .mov or .wmp. (.mkv is normally used for higher quality and will result in huge file sizes which will likely be a problem to email).