When email is sent between 2 people with accounts on an Exchange email server, the email addresses that are used are not the typical and familiar SMTP-style email addresses. An Exchange user’s SMTP email address may be email@example.com, but Exchange uses an address that is based on X.400 (or X.500) and this user’s address would look like this: /O=SOME_COMPANY/OU=EXCHANGE_GOUP_1/CN=RECIPIENTS/CN=JOEBOB
And, when the Exchange client stores the email message, for example, when Outlook writes the message in the PST file, the client often stores the Exchange-style address only. The SMTP version of the email address is simply not written in the message record.
When you go to migrate this email to another email app, this can be a problem if you are not moving your mail to another Exchange server environment. Maybe you are converting an old PST file to something you can read in Thunderbird or Gmail, for example. The problem is that the original SMTP address is not in the source data and there is no direct mapping of the Exchange-style address to a SMTP address. So, Emailchemy handles this 3 different ways:
1) Include the Exchange-style addresses as-is. This preserves the original data, but the address won’t be routable by SMTP in downstream processing, of course. And, it might actually cause some email clients to not render the message correctly.
2) Try to convert it to SMTP-style. Emailchemy will create a valid-formatted SMTP address out of content found in the Exchange-style address. It will look like user@company, where company will be the org name from the Exchange address, but it won’t have a .com or .net at the end and the address won’t be routable. In our example above, it would generate joebob@somecompany. This will keep downstream email clients from breaking, and you’ll have an idea who this is, but you won’t be able to send email to this address.
These first 2 options are selectable in the Emailchemy GUI and CLI. This last one is in the API only.
3) Emailchemy’s API has a callback function that you can implement to do a lookup of the SMTP address in an Active Directory server