When I send an email with a large-ish file (2MB or greater) outlook 2016 appears to take many attempts to send it. Each attempt results in a full entry in the sent folder. This can result in tens of MB of data which counts towards my postbox size quota. I sent ten 2MB files yesterday and my sent box filled up with multiple copies of each and I exceeded my postbox size limit (over 10GB in one day!). This froze all my emails in and out.
If outlook is failing to send these large files why is it recording every attempt in the sent folder? Shouldn't it just store the one that it does successfully send?