Cloudron 10.0.3: MXGuarddog SRS-forwarded mail rejected when MAIL FROM local-part exceeds 64 octets

[mariolop77]

Cloudron 10.0.3 / Haraka 3.3.2

After upgrading to Cloudron 10.0.3, inbound mail forwarded
through MXGuarddog is being rejected when MXGuarddog's
Sender Rewriting Scheme creates an envelope sender local-part
greater than 64 octets.

Example:

MAIL FROM:
SRS0=FNUu=G2=em.brighttalk.com=bounces+3639386-906e-andy=azaz-tech.com@ik2.com

Cloudron response:
501 Invalid MAIL FROM address ... RFC-5321 local-part exceeds 64 octets

Shorter SRS0 addresses from the same MXGuarddog servers are
accepted and delivered normally.

[girish]

We switched to https://github.com/haraka/email-address and it seems by default it is quite strict. See https://github.com/haraka/email-address/blob/4bea96181e4db2718cc523876856e2c0f32ea7fc/lib/address.js#L163 . I have to set the postel option on our mail server.

[mariolop77]

Thanks for reaching out @girish. I also reached out to MXGuarddog to see if they can trim on their side. As of now, many emails are bouncing. I might need to bypass MXGuarddog for now until there is a fix if you can fix.

[girish]

@mariolop77 a temporary workaround is

docker exec -it mail /bin/bash

Then edit /run/haraka/config/connection.ini . Add postel=true like this in the main section:

[main]
smtputf8=true
postel=true

<rest of the file>

Then supervisorctl restart haraka . This config file gets overwritten on server restart, so you have to do this again.

[mariolop77]

Thank you @girish!

[mariolop77]

@girish I just wanted to relay that this workaround works.