If you deleted them within the email account, you will have to check with the email hosting company to see if there is a way to recover them.
However, if you deleted them on the phone, and are looking to recover them through email, that isn't possible to just 'recover' them. If you had the phone synced to the account, and updated that sync regularly, then the files should be there in the account. If you didn't have that set up, they won't be there.
You can try the following to 'maybe' recover some or all of them from the phone...
There are a few apps/programs out there that 'may' be able to help you recover the data.
A few of the programs you could try would be... DiskDigger, MobiSaver, Android-Recovery and Tenorshare. They are all...