On-prem Exchange 2013 EWS (Basic over HTTPS, live-probed) becomes a second
selectable email transport beside SMTP: additive SmtpConfiguration.Transport
discriminator, hand-rolled CreateItem SOAP sender (no SDK, BCC-only,
SendOnly), EwsErrorClassifier mirroring the SMTP transient/permanent split,
CLI/UI transport selector, fake-EWS unit stub + one-off live gate. The
pending O365 SMTP-OAuth2 verification (Q12) is superseded — real mail infra
is on-prem EWS. Design only; no implementation. Also gitignore the untracked
dev-credential file email_details.txt.
Joseph Doherty