One thing that would be nice: being able to see aggregated statistics in your dashboard. It would be useful to see errors/warnings for all domains, and also seeing the total number of send/received mails.
Anurag Deshpande commented
option to check total mails sent in a month via API could be a great add on for developers instead of writing scripts to run through all the dates in the response, please consider this feature for addition, can save a lot of time
I used to be able to delete bounced e-mails. Now, you've got them listed as something else and I can't delete them, only view. This is very unwieldy for our organization as I only work P/T (about 40 hours per month total!). I