Mail will not connect to server
I have had this problem since I put Lion on this macbook years back. However it has been working for a while until today. All the Gmail accounts (3) would not download mail and stayed off line. I tried the tricks I had tried before like finally deleting the Gmail accounts all together. The iCloud account is fine. I really need to convert everything to that but I'm sure I'll miss an important one. Anyway I can't add the 3 accounts back in to Mail. When I try I get the message "Connection failed". Mail is working fine on a 2014 iMac, iPad, and iPhone so the connection is fine. I realize this has always been a problem on this computer and Lion, and if this continues, I have a reason to get the Macbook Air that I want. However I'd like to try to fix this if anyone has any ideas. Thanks
MacBook, Mac OS X (10.7.5)