Wordpress & Phpmailer : data not all cleared

[danygold]

When sending several emails successive, not all data are cleared from phpmailer.
In my case, I'm sending two emails :

• One first email validation in HTML (with text and Html as altbody)
• One second email with some raw data, and custom content-type.

The second email keep the variable "AltBody" from the first email, so wp_mail consider it as a multi part email. And as so, wp_mail() change the content-type from my custom kind to "multipart".

It comes from the re-use of global $phpmailer, instead of create a new phpmailer.
Phpmailer class needs a better clear of all previous variables.

[stephenharris]

Duplicate of #33972.

[stephenharris]

Thanks for reporting this @danygold. This issue is being tracked in #33972.