Is there a way to generate emails on Exchange with past sent/received dates - email

Question

We have a component that grabs emails/meetings from Exchange (Online, 2013, 2010) and we'd like to create email distribution in the past timeframe e.g. 6 month for testing purposes.
In order to achieve this we definitely need emails that have received/Sent dates to be in the past, not started from current (from generation moment) time when we started email generation.
We looked at EWS API - it does not support changing of the dates for created (generated) emails.
What other options exists?

Answer 1

You can create an Email with EWS that looks like it was received in the past if you change the Extended properties on the message eg
EmailMessage OldMessage = new EmailMessage(service);
OldMessage.ToRecipients.Add("user#domain.com");
OldMessage.Sender= new EmailAddress("bob#domain.com");
OldMessage.From = new EmailAddress("bob#domain.com");
OldMessage.Subject = "This is an old message";
OldMessage.Body = new MessageBody("test");
ExtendedPropertyDefinition PR_Flags = new ExtendedPropertyDefinition(3591,MapiPropertyType.Integer);
OldMessage.SetExtendedProperty(PR_Flags,1);
ExtendedPropertyDefinition PR_CLIENT_SUBMIT_TIME = new ExtendedPropertyDefinition(0x0039,MapiPropertyType.SystemTime);
ExtendedPropertyDefinition PR_MESSAGE_DELIVERY_TIME = new ExtendedPropertyDefinition(0x0E06,MapiPropertyType.SystemTime);
OldMessage.SetExtendedProperty(PR_CLIENT_SUBMIT_TIME,DateTime.Now.AddMonths(-6));
OldMessage.SetExtendedProperty(PR_MESSAGE_DELIVERY_TIME,DateTime.Now.AddMonths(-6));
OldMessage.Save(WellKnownFolderName.Inbox);
You can also just import a message using the MimeContent that would do the same thing eg https://msdn.microsoft.com/en-us/library/office/dn672319(v=exchg.150).aspx
Cheers
Glen