Even adding the SMTP server manually in Mail didn't help. Her outgoing email account (SMTP server) for a Gmail based email account kept appearing 'Offline' right after she set it up. I'm hoping that Catalina fixes this.I originally wrote this post when I helped a friend with her outgoing email in Apple Mail. I'm reduced to using gmail on the web and using Apple Mail for my other accounts, but this is a pain. I haven't done it because I need to conform to the HIPAA security rule for medical information. Google says that Apple Mail isn't secure enough I doubt it! There is one option I haven't tried, which is to change the Google setting to allow less secure apps. Google also has a little page you're supposed to go to and sign in if you're having problems like this that didn't work either. I've tried the app specific password, the regular password, over and over. Now, a new app specific password doesn't help.

Once before, it stopped working, several years ago, and I got an app specific password and that corrected the problem. It has been set up with IMAP for incoming mail and SMTP for outgoing for years. I have used Apple Mail successfully for years to access my gmail account. I use two factor authentication with my google account and have for years. This actually occurs more often than you think. Let less secure apps use your account - Google.Using app-specific passwords - Apple Support.The following articles should help with this one: This may require that you use an app-specific password, instead of your normal password, to use with your gmail account in the Mail app. You enabled two-factor identification on your Google account.

If you can send a message from there, then you know your credentials are correct. You can test this by accessing your gmail account using a web browser, instead of the Mail app. This should be your gmail address and password.

Your SMTP server user credentials are not correct.

These may not necessarily be exactly the same for you, but most likely, they will be. For example, after I entered mine, I got to be the server name and 587 for the secure port number to use. To check for the correct SMTP server settings for Gmail, I suggest that you enter your Gmail email address in the following Apple support article and it should provide them for you.

The SMTP server settings in the Mail app is mis-configured.

One, or more, of the following could be the reason(s):

So, in your case, the issue appears to be with Google's (send mail) server. When you send messages, you use your provider's SMTP server to do so. This is how the Mail app can retrieve messages that are sent to your email account. IMAP (or POP3) is your email provider's incoming mail server.

Mac mail outgoing settings