Microsoft engineers are struggling to fix a seven-day-old, self-inflicted Office 365 IMAP outage.

IMAP access to Office 365 tanked on January 18, meaning customers could not access emails using Exchange Online via IMAP or connect third-party mail clients via IMAP.

Microsoft told disgruntled Office 365 customers that the problem affected a limited number of licensees – but that those customers hit had a “large number of users.”

The culprit was found to be a botched Microsoft update that stopped the IMAP protocol automatically loading data from Exchange Online databases.

Source: Microsoft struggles against self-inflicted Office 365 IMAP outage

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