Error when sending E-Mail to certain providers because of SMTP protocol violation

Using my Dolibarr Other native modules
1

Hey there,

since my update to 20.3 mails send by dolibarr bounce when sending invoices via E-Mail to certain customers.

The error I get on the failed delivery report mail is:
SMTP error from remote server for TEXT command, host: smtpin.rzone.de (81.169.145.97) reason: 554 5.6.0 SMTP protocol violation: A header line must be terminated by CRLF

It seems like certain Mail-Service-Providers (here Strato) are blocking the E-Mails, while others (Telekom, Proton, Web.de) are accepting the messages. I suspect that Dolibarr is encoding the Mail-Header in an non RFC-Compliant way, since Stratro recently started enforcing RFCs more strictly.

Did anyone of you also have a similar problem and / or has a solution?

Many thanks!

Greetings,
sn0b4ll

Edit: Typos

2

oh, where do you see the error report? does it bounce back to you, or is it in the mailserver log?

3

Hey :wave:

it bounces back to my mail account. The sending itself looks fine, seeing no errors in the logs of dolibarr.

4

does it state which header is the issue?

My expectation is that it is a PHP library that actually sends the email, which PHP version are you running?

Could it be something that your SMTP server adds before sending it on?

5

Hey :wave:

sadly no, just that overall error and afterwards the mail itself.

I noticed that the subject and nail addresses are encoded in utf-8, while they should be ASCII according to the RFC? But that’s a wild guess from my side.

I can give you feedback on the version in the upcoming days, but I am using the docker version. I will check when I am at the location again.

The SMTP server is not the problem, I am able to send mails via Thunderbird and the same credentials to addresses that bounce when addressed via dolibarr :confused:

6

If you use the docker image, there is no reason to supply the PHP version, that can be inferred from the docker image.

Okay, that does not seem to be a SMTP server issue - through probably IP address and/or username is different for your Thunderbird and your Dolibarr.

I think you should report the issue on github as a bug, and include as much information as possible.

7

I had a similar issue after dolibarr update from 19.0.2 to 20.0.3 with following Error using Strato Server
"error during sending E-Mail (Sender=my companymy@domain.com, Receiver=me@domain.com)
Error [120]: Ran into problems sending Mail. Response: 554 5.6.0 SMTP protocol violation: A header line must be terminated by CRLF "

i changed from SMTP/SMTPS socket library (works on 19.0.2) to Swift Mailer socket library (works on 20.0.3)
all other settings remain the same.

brgds
Joey