Mail to receiver "Frontend User Group" does not work with large groups

[seitenformate]

Hello,
I'm trying to send a mail to a frontend user group. It works with one or two receivers. But not with 30. I have changed the size of receiver_mail in tx_powermail_domain_model_mail (from varchar(255) to text. But it still does not work. In the documentation I cannot find anything. Do you have an idea?
Best regards,
Alex

[einpraegsam]

30 is a number that can lead to a timeout on sending mails. Powermail is only a simple contact form extension and not a newletter-system. I think it's not possible in the described use case.

[seitenformate]

Ok. Thank you!