Slow downloading email attachments

Hi, to everyone on this forum. This is my first post as this is my first problem I've had with my Imac since I purchased 2 years ago. I have a Imac desktop that has 4 GB of ram that is connected to my Verizon Fios internet router through a ethernet cable and has run great with no problems until now. When I receive an email with a larger attachment it takes longer then usual to download also if I send the same attachment it is slow to send. To give a example a 3 MB attachment takes 2 minutes to receive and 1 1/2 minutes to send. I have a windows 7 desktop computer connected wirelessly to the same router and it receives the same 3 MB file in 50 seconds and sends it in 12 seconds. I have ran a speed test on my Mac and I'm getting 83 Mmps on download and 35.6 Mbps on upload. That is consistent with the 75/35 Mbps speed package I have with verizon. I've talked to Verizon tec guy who had me delete my email account and then add it back on with new incoming and outgoing server names and port settings that Verizon has updated and still the same slow download and sending speeds with attachments. Email sends and receives fine with no attachments (just text). Surfing the web is also ok. Verizon says it has to be in the Mac's email program since the Windows 7 computer receives email fine. I have ran a disk permission repair and did mail box rebuild and still the same slow email. Also check activity monitor and nothing is hogging CPU resources. I don't remember my email downloading attachment this slow in the past, but maybe compare to download time others on this forum are getting maybe it might be my imagination. I also like to add that I do not have any anti-virus programs running on my Mac. Any help would be greatly appreciated.

Thanks

Hi and welcome,

You seem to be right on top of things so it could be just a maintenance issue..(caches perhaps ?)

There is a great free app called Onyx that a lot of us use on here. You can get it here Download OnyX for Mac - Maintenance and optimization tool. MacUpdate.com to suit your OS version.

After it's done the smart verification run the 'Automation' tab and see if that helps.