Technical Note: FortiMail - Email is rejected with 'SMTP authentication failure' using Microsoft Outlook
This brief offers a quick and basic guide to solve the issue in FortiMail Server Mode, when an end user is using Outlook and the emails are being rejected by “SMTP authentication failure: authid=, authtype=DIGEST-MD5, detail=SASL(-6): can't request info until later in exchange: Information that was requested is not yet available”.
Solution
Usually, this issue “SMTP authentication failure: authid=, authtype=DIGEST-MD5, detail=SASL(-6): can't request info until later in exchange: Information that was requested is not yet available” is associated to Microsoft Outlook 2007/2010, when the email server uses Digest-MD5 as authentication method. Outlook doesn’t understand this proposal and sends wrong credentials.
To avoid this behaviour, Microsoft team recommends to identify and erase into the register key, the protocol Digest Authentication (Wdigest) and erase it.
Follow these steps:
- Open the Registry Editor (run “regedit”)
- Find [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa]
- In Lsa, select "Security Packages"
- Now, deleted "wdigest" from the list
- Restart the PC
