wp_mail() not able to send/deliver emails to domain with hyphens in it?

[verya.ca]

I tested many plugins and all of them, who uses wp_mail(), are not sending/delivering emails to domain with hyphens in it.

I tested on 3 different hosts, with 4 different domain names. When an email is sent to a domain with hyphens in it, it's not delivered. Seems like the "sanitizing" process is causing an issue maybe?

[davidbaumwald]

Hi, @verya.ca, and welcome to WordPress Core Trac!!

I think that you may have some plugin/theme interacting negatively with wp_mail. For some perspective, my own business domain is hyphenated and has not experienced this issue.

Please check in with the support forums at ​https://wordpress.org/support/forums/, and maybe they can help you better pinpoint the issue.

If, however, it's confirmed there is indeed a bug in WordPress Core and the wp_mail function, feel free to reopen this ticket with more information.

[verya.ca]

In a newly installed WP, without any plugins installed, if I use the wp_mail() function directly in the Twenty Twenty One theme, it's not working. I tested on different hosts with different email addresses.