Bruno César da Silva

this is the result of $mail->SMTPDebug = 2;  this is how the sending of the email is configured  does this problem have anything to do with XAMPP...

sorry what line would be the transfer encoding?

it worked with these settings, thank you very much! I removed the line: `$mail->addCustomHeader('Content-Transfer-encoding:` 8bit `\r\n');` and removed all the \r\n from the header

@Synchro I'm having the same problem again, but now the issue occurs when I attach a certificate to the email. When I remove the certificate, the problem doesn't happen. Have...

I've already done that, removed the 7bits, set it to 8bits, and left it empty. The issue is that when I don't set the encoding to 7bits, it gives an...

Apparently the issue lies with the signature itself; when removing the signature $mail->sign(), everything works perfectly.

 @Synchro In this test I performed, the email was sent without a signature, and if you observe in the log, it contains strange characters, yet the email is received...

@Synchro Do you want me to capture the output of $mail->SMTPDebug = 2; with the signature?

**This first one is an example with a signature** 2024-02-05 17:06:21 SERVER -> CLIENT: 220 ###### 2024-02-05 17:06:21 CLIENT -> SERVER: EHLO localhost 2024-02-05 17:06:22 SERVER -> CLIENT: 250-#####.####.####.##250-PIPELINING250-SIZE 68500000250-VRFY250-ETRN250-STARTTLS250-AUTH...

@Synchro I thought it was better to put it as an image because text gets disfigured. This first one is an example with a signature:  ![log...