Our mail.dll sets up "mail.dll" as hostname in part of the email message id, e.g. Message-ID: 70e6f0cf-cc46-40d5-a139-8365a70631aa@mail.dll.
I would like to change this part to another domain. Is this possible?
You can use MailBuilder.MessageID property to set mail's message-id header yourself:
var builder = new MailBuilder(); builder.MessageId = Guid.NewGuid() + "@example.com"; .... IMail email = builder.Create();