I noticed that rspamd gives spam points for the Message-ID in my mails, and there is no way to configure claws-mail easily in a way that would prevent it. By default, claws generates a Message-ID of the form [datetime_as_number].[somethingrandom]@[hostname] The hostname is the local configured system hostname, which is usually not a valid domain name. rspamd has a rule for that called MID_RHS_NOT_FQDN which gives 0.5 spam points. claws has an option "Send account mail address in Message-ID" in theh account settings that generates a message id of the form [datetime_as_number].[somethingrandom].[mailaddress] This avoids the above, as we end up with a valid FQDN, but rspamd has another rule MID_CONTAINS_FROM that matches here if the full mail address is contained. I should say here that, as far as I can tell, neither of those are invalid according to mail specs, and I do not know what the motivation for those rules in rspamd is or whether they are particularly wise. But from a pragmatic point of view, and knowing that rspamd is widely used, I'd prefer to send mails that do not needlessly trigger spam classification rules. Looking at mails from other applications and senders, it seems to me that overwhelmingly, it is common practice to have Message-IDs of the form [some_random_token]@[some_valid_hostname] The hostname is not necessarily the one of the sender, but it can be. I would suggest that claws provides a way to have a Message-ID of the form [datetime_as_number].[somethingrandom]@[maildomain] It may even be a good idea to make this the default.
There is per account setting, accessible via menu item 'Configuration' -> 'Edit accounts...', select account and push 'Edit' button. Now, in 'Account preferences' dialog window, select 'Account' -> 'Advanced' page, and here you are... Third line from top is marked with 'Domain name' label, and, if checked, this is used to create a Message-ID header. So what you want to achieve, is already here, just not default, you need manually enable the option and put your desired domain name into input field. Maybe this could be better documented, I just leave this for you to check and possibly write a docs enhancement request.
Thanks. I can confirm this does what I want. I think a note in the settings for the message ID might be useful. I'll check it and see if I can come up with a patch.
Created attachment 2529 [details] Add note about Domain name option under "Advanced" for Message-ID option Here's a patch that would make it easier for people looking how to configure this in the future. Feel free to apply or ignore. Given that the issue is "resolved for me", I'm okay with both.
Your patch is not a good approach. If we're going to include such info then it should be complete and in a tooltip. But where would this end, if everyone wanted the particular option that interests them explained in the UI? Better than this, add it to a suitable page in the FAQ: https://www.claws-mail.org/faq/index.php/Main_Page