I can't send email with my Mac. It receives and both addresses are able to work on the websites. This comes and goes, very frustrating. The internet provider says it's Apple and Apple says it's the provider. It works well on my other devices.
I have been using the Mac mail app, but added Outlook to see if it solved the problem.....NO! Both apps won't send consistently. HELP!
iMac 27″, macOS 10.12