wp_mail conflict with Post SMTP?

[mtlsam]

Whenever I have this plugin activated, it prompts this warning in the Post SMTP plugin settings:

“Postman: wp_mail has been declared by another plugin or theme, so you won’t be able to use Postman until the conflict is resolved.”

This happens even with none of the headers turned on. I also did a search of your plugin’s files and foundn no reference to the wp_mail function, any idea why this is happening?

Thanks.