On Thu, 18 Nov 2021 21:03:43 -0000 (UTC) Jasen Betts via Exim-users <exim-users@exim.org> wrote:
> On 2021-11-18, Andrea Biscuola via Exim-users <exim-users@exim.org> wrote: > > Hi all > > > > We are an italian hosting provider (https://host.it) and we use exim to > > relay e-mails from > > our hosting servers. > > Exim is installed and configured through the directadmin control panel > > (https://www.directadmin.com), so the main configuration is managed using > > the > > directadmin custombuild subsystem. > > > > One week ago, we upgraded to exim 4.95 and suddenly, some customers (using > > microsoft > > outlook, nonetheless), started to experience the following error for *some* > > of their > > e-mails: > > Outlook is not email software. Outlook is X.400 software with partial email > capability tacked on. We all agree on that. > > > message has lines too long for transport > > Reporting-MTA: dns; web017.shared.host.it > > > > I received some examples of such e-mails from our customers service, and it > > appear that > > the problem is with some badly formatted headers. > > > Unfortunately, we can't throw those customers out of the window :-) so we > > are searching > > how to expand the line limits for the transports. > > Turn off 8BITMIME. that may be sufficient to prevent this outlook bug. > perhaps configure two different submission ports one with 8BITMIME > disabled for the benefit of those afflicted with outlook and one with > all the features enabled. On another thread it was mentioned that it could be possible to fold the "References" header, splitting it on multiple lines. I think it could be a better solution than increasing the limit, would that work? > > > However, I'm struggling to understand, from the documentation, what the > > correct solution > > is. From what I was able to understand, we should modify the remote_smtp and > > remote_smtp_forward_transport sections to solve the problem, with the > > message_linelength_limit > > parameter set to something like "4096". > > The important documentation is here: > https://datatracker.ietf.org/doc/html/rfc5322#section-2.1.1 > I already checked the relevant RFC, thanks. > > Consider also, that the main exim configuration, is handled directly by > > directadmin and > > it's generated from it's internal "templates". In general, we can safely > > change a configuration > > file called /etc/exim.variables.conf.custom to put a series of overrides to > > the default > > configuration. > > > > Do we need to modify the directadmin templates or can we use one of the > > "custom" files > > in /etc to achieve the same result? > > Increasing that limit will break SMTP and will probably just result in the > refusals > taking longer to reach the sender. > Andrea -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
