OK, I managed to send via mutt. Thanks!
It worked when I set both from and envelop_from to my gmail address.
I guess my ISP is doing something clever by checking that the sender email address actually exists...?
- Re: mutt with exim4 smtp smarthost rejects mail Alex
- Re: mutt with exim4 smtp smarthost rejects mail Andrew Sackville-West
- Re: mutt with exim4 smtp smarthost rejects ... Jon Dowland

