D4niel “Specific attachments” - That’s not really something to work with. What attachments? Do you have logs (Postfix, Rspamd etc.)?
xtt D4niel thank you for your help I found that the problem is the attachment cannot be more than 50 m, by modifying the data/conf/rspamd/local.d/options. inc configuration max_message = 500 MB;
c-rra xtt It doesn’t work. When i set max_message = 150 MB; the error is “cannot send message: (smtp) authentication failure”. Also i tried to set max_message in bytes, but in this case also was 4.7.1 error