I have a server that is running a PHP app through docker. In it, I'm using the PHPMailer package to send an email through another server I have, which has postfix running. When I send the email, I get this error:
2022-03-27 00:29:03 SERVER -> CLIENT: 220 mydomain.com ESMTP Postfix (Ubuntu)
2022-03-27 00:29:03 CLIENT -> SERVER: EHLO d9757e7e26c2
2022-03-27 00:29:03 SERVER -> CLIENT: 250-mydomain.com
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-STARTTLS
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
2022-03-27 00:29:03 CLIENT -> SERVER: STARTTLS
2022-03-27 00:29:03 SERVER -> CLIENT: 220 2.0.0 Ready to start TLS
2022-03-27 00:29:03 SMTP Error: Could not connect to SMTP host. Connection failed. stream_socket_enable_crypto(): SSL operation failed with code 1. OpenSSL Error messages:
error:1416F086:SSL routines:tls_process_server_certificate:certificate verify failed
2022-03-27 00:29:03 CLIENT -> SERVER: QUIT
2022-03-27 00:29:03 SERVER -> CLIENT: M
IAx+�P^�r���+����wkշCqW�����
�{�!/�loj����c@�탇�2��6�]u��<'C1`3��8|��v�
��&�e8���=���W�k�[QM3��r��q�����]��9�٭�I0�Sh�����?�P���f��zS�ZrȽS�����x�
W�P�_��$HJ�2�9��(+��gA�3'��s�YkL.͟�,v�zc+}7�_4Q- ��[�W9�Sl�FQ�sӾ�S�6<g/#�kF ���P8 }�����n�|�+;7B�dhV;|!�4�z����J
2022-03-27 00:29:03 SMTP ERROR: QUIT command failed: M
IAx+�P^�r���+����wkշCqW�����
�{�!/�loj����c@�탇�2��6�]u��<'C1`3��8|��v�
��&�e8���=���W�k�[QM3��r��q�����]��9�٭�I0�Sh�����?�P���f��zS�ZrȽS�����x�
W�P�_��$HJ�2�9��(+��gA�3'��s�YkL.͟�,v�zc+}7�_4Q- ��[�W9�Sl�FQ�sӾ�S�6<g/#�kF ���P8 }�����n�|�+;7B�dhV;|!�4�z����J
2022-03-27 00:29:03 SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting
Mailer Error: SMTP connect() failed.
It was suggested I install ca-certificates on the docker container, but that didn't help. I'm really not familiar with emailing, so I'm not sure what certificates are missing, or what I have to add.
