Reopend as I resolved the wrong (older) one.

Has something changed recently, HTML emails used to work.
I think this is more than a nice to have as it breaks the "forgot your password" link in the email

this patch worked for me.
https://www.mantisbt.org/forums/viewtopic.php?f=4&t=3786

this patch worked for me.

This patch enables HTML email.

The current issue is a different thing, it's

option to strip HTML from text-only e-mail

Here below the email content.

• HTML is in plain text
• the URL contains "&" instead of "&" which breaks the link

I got the problem when I upgraded from mantis 2.2.1 to 2.6.0 (using same config files, same plugins)
but most surprisingly, when I rolled back to v2.2.1 the problem was still there !
So I searched for any configuration concerning email in the mantis_config_table but could not find anything that could have changed.

To make it work again, I had to hard-code "$t_mail->IsHTML( true );" in core/email_api.php

So I'm realy puzzeled, because how could it work before if HTML is disabled in the code ?
It can only be some configuration issue (as rollback did not work) but where ?

Someone (presumably you) requested a password change through e-mail verification. If this was not you, ignore this message and nothing will happen.<br /> <br /> If you requested this verification, visit the following URL to change your
password: <br />
<br />
<a target="_blank"
href="https://my_fake_server.net/prjmngt/mantis/verify.php?id=2&confirm_hash=A8D6015EJZtAvfip601Q0ujFRawJY3U9zbHYsQ8aqCXUbmmcr_vvFy6HMDht0PzxddEKBORRcp57y76Fd8Cw">https://rsitools.bs.fr.myatos.net/prjmngt/mantis/verify.php?id=2&confirm_hash=A8D6015EJZtAvfip601Q0ujFRawJY3U9zbHYsQ8aqCXUbmmcr_vvFy6HMDht0PzxddEKBORRcp57y76Fd8Cw</a>
<br />
<br />
Username: lbayle <br />
Remote IP address: 172.23.138.66 <br />
<br />
Do not reply to this message

In my previous message, Mantis seems to have processed the "plain-text HTML" as real HTML, so the sample text is useless.
Nevertheless, you probably understand what I meant

In my previous message, Mantis seems to have processed the "plain-text HTML" as real HTML, so the sample text is useless.

I quoted the text so the HTML tags are not rendered.

Simplier than an option, shouldn't HTML tags in summary and description get stripped in text email format?