Exchange

Screenshot of XBill

Fun with Microsoft Exchange.

Exchange protocol bugs

Microsoft Exchange server has several protocol bugs which you may need to work around.

Failure of plain authentication

You get the following error message: Retrying PLAIN authentication after AUTHENTICATE failed. This is because Microsoft Exchange protocol mistakenly advertises plain authentication even though it does not support it. You need to force the email client to ignore this. E.g. with alpine

disable-these-authenticators=PLAIN

Kerberos authentification failure

You get the following error messages: Unknown Kerberos failure: An invalid name was supplied and Kerberos mechanism status: Hostname cannot be canonicalized. This is because Microsoft Exchange protocol mistakenly advertises kerberos authentication even though it does not support it. E.g. alpine users need to add this option

disable-these-authenticators=GSSAPI

Workaround both problems

To work around both problems you need to disable plain authentication as well as Kerberos host authentication. E.g. with alpine

disable-these-authenticators=PLAIN,GSSAPI

External Links

• Exchange problem: Message to save shrank (also see alpine changelog)