I keep having issues with my mail. I can send, but not receive. This is the message I keep seeing. 'The server returned the error: An SSL error has occurred and a secure connection to the server cannot be made.'

Hello there, em89ma.

It seems you're having issues receiving an error in regard to an SSL error occurring due to not being able to make a secure connection to the server. The following Knowledge Base article offers up some great steps to look over for troubleshooting:

If you can’t send or receive email on your Mac

If Mail refers to a problem with the mail server or network

Mail might say that it’s unable to connect because of a problem with the mail server or network. For example, the message might refer to a connection that timed out, or too many simultaneous connections:

If you're connected to the Internet but the connection timed out, your email provider could be experiencing a service outage. Contact them or check their status webpage to make sure that their mail service is online. Examples of status pages:

• iCloud mail status
• Gmail status
• Yahoo mail status
• AOL mail status
• Outlook mail status

If the message refers to the number of simultaneous connections, too many of your devices are checking your email account at the same time. Quit Mail on one or more of your other devices.

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If you still can’t send or receive email

1. Make sure that you installed the latest Mac software updates, especially if the issue occured immediately after installing a previous update.
2. In OS X El Capitan, you might see a status icon and brief error message in the upper-right corner of the Mail window, beneath the Search field. The message might say “Network Offline” or “Login Failed,” for example. Click the message to see more details about the issue.
   
3. Check your connection in Mail Connection Doctor. It might be able to tell you more about the issue.

Thanks for reaching out to Apple Support Communities.

Kind Regards.