The Steps Involved
The first option is to remove the affected email account from your BlackBerry, pull out the battery, insert the battery, turn on the phone and then add the account all over again.
The second option is to check the types of email accounts on your BlackBerry smartphone. Unknowingly, some users have both BES and BIS email accounts on their phones. This can cause a problem in some cases. For instance, the BIS account might get a copy of an email from the BES account using POP. This will then cause a duplicate email to be sent to the phone. The way to fix this problem is to remove the BIS account from the BlackBerry.
If your BlackBerry smartphone only has a BIS account, the way to fix this problem is to remove the BIS account from your smartphone and install a BES account to fix the problem completely.
A BlackBerry receiving old mail is a common problem among users but it can be fixed using one of the methods mentioned above. Should none of these methods work, take your phone to your service provider's nearest location for a solution.