Could not instantiate mail function on admin email

[sandomatyas]

Lately, I've noticed something strange in my VirtueMart shop. When customers place an order, they receive their email confirmation, but the admins sometimes receive it and sometimes don't.

I dug a bit deeper and found this:
When VM sends the vendor email, there is a Reply-To address, which is set to the customer's email. However, in the last few months, SpamAssassin has been refusing to send the email, and I receive the error message: "Could not instantiate mail function."

I contacted the hosting provider, and they claimed that it's not standard to have a Gmail address in the Reply-To field because Gmail's settings do not allow this.

When I modified some core code to remove the Reply-To field, I started receiving all the emails.

Would it be possible to disable this Reply-To setting?

[hazael]

What your hosting administrator mentioned might not be entirely accurate. Everything works perfectly fine for me, and my mail system functions without any issues.

It's possible that your mail server has a low reputation, which could be causing the emails to not reach the recipients. If you share your domain address, I can take a look and help identify any potential issues.