My macBook will download my mail but I am unable to send mail out.

There are a few things that may contribute to your Apple Mail setting issues.

Depending on your macOS version, this article can be adaptive; for systems

between High Sierra, Mojave, Catalina, and Big Sur. [Select your Mac system.]

• Troubleshoot email problems in Mail on Mac - Apple Support (catalina)

https://support.apple.com/guide/mail/troubleshooting-mail35552/13.0/mac/10.15

Mail support sites have several links to try & check, and re-set; then test your Mail.

• Mail Help - [Table of Contents] - Apple Support

https://support.apple.com/guide/mail/toc/11.0

Sorry to not have exacting steps spelled-out ~ this covers most issues.

Take care & good luck!

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