Mail cannot receive or send message resolution in MacBook

　　Method One:

1, open "Mail" to find preferences, to find "advanced"

2, the "Automatic detection of Account Settings" and "uncheck" Exit, and then open "Mail" and then check it again

　　Method Two:

1, please check SMTP settings

2, the recipient address can try to change a

　　Method Three:

If Sina no problem can automatically set up, suggest using IMAP , do not use POP3

"Note" VIP Mailbox open IMAP function, some mailboxes need to manually open.

　　Method Four:

1, open "Mail" to find preferences, to find "advanced"

2, directly uncheck "Use mail drop send large attachment"

I will continue to add to the "MacBook Mail cannot receive or send mail solution " and hope that the tutorials are helpful to you!