Sending Mails with 8bit Content

AXIGEN returns a NDR message: 'Unable to relay - necessary MIME encoding not supported'

When relaying e-mails that contain 8bit characters (like diacritics), AXIGEN checks that the remote mail server supports the 8BITMIME and BINARYMIME ESMTP extensions (only one of them is sufficient for AXIGEN to successfully send the relay message). Sometimes, even though the remote ESMTP servers support receiving 8bit messages, they don't advertise these extensions when an EHLO command is issued and causes AXIGEN to send back a NDR (Non-Deliverable Reply) message to the original sender, containing the error message: "Unable to relay - necessary MIME encoding not supported".
There are two ways to solve this with different results, one at email clients level and one at AXIGEN server level:
1. Set your e-mail client to be 'MIME Compliant (Quoted Printable)' for 'Message property' setting. This will solve it only for this e-mail client and will be able to send e-mails to.

2. Edit your SMTP Filters Policy file and add the following in code in the "onRelay" event definition:
- for a specific domain, only:

if (is(remoteSmtpHost, "example.org")){
set(strict7BitMime, "no");
}

Where 'example.org' is the domain name of the receiving MTA that AXIGEN can't relay the mails to.

- for all domains:

set(strict7BitMime, "no");

This will solve it at server level, and all accounts will be able to send e-mails to that MTA, regardless of settings from the e-mail client used.