Apple Mail Can't Send but other Programmes Can
This's not my first question. Starting from late last year, early this year, I found that, under the same system, i.e. 2017 iMac 27' 5k running the latest High Sierra macosx, I could not send out email successfully with Apple Mail, but found it succeeded with other Mail application, e.g. MS Outlook or Firefox Mail, etc.. I have verified with Mail preference, connection doctor, the said mail smtp server was connected, but just simply nobody can receive my email. Any body has an idea to solve it? Thanks in advance.
iMac with Retina 5K display, macOS High Sierra (10.13.2), 32MB RAM, i7