I have an issue with Office 365 relay. I have an application that sends e-mails to various external recipients. The senders are from domains other than ours, they relay through our on premise exchange 2010. I have setup the connector and can relay through 365 but the sent from account has to be from my domain.
ex mail sent from: Linda@contoso.com relayed via on premise exchange mail.contoso1.com,
when attempting to relay via Office 365 the sent from name gets rejected, the mail sent from has to be an authenticated account in contoso1.com. Does anyone know if this can be done or a work around? I have 5 different domains that relay these messages through my of premise and there e-mail addresses need to be in the sent from field, these are tax bills, water bills and EFT payments and pay stubs. Microsoft says that it cannot be done and I...