Why is the site's email-in address generated so complicated?

The email address uses a formula that includes a token and makes it appear rather long and complicated. This is intentional, as the email address is intended to be a private address and so the token is necessary. This serves two purposes: 1) it prevents the situation where someone submits documents to the incorrect site (i.e. they have a typo and end up sending their site documents to Site02 or Site10 rather than the intended Site01); 2) it makes it harder for people to guess emails for other sites or other studies.

If the long email address is a problem, your IT group could setup a simpler email alias with forwarding to SimpleTrials. That would be handled by your internal IT group.