Microsoft has mounted a recognized subject affecting Outlook for Microsoft 365 customers that triggered issues sending emails for these with too many nested folders.
When it first acknowledged the email-sending points in December, the corporate linked them to an older downside associated to mailboxes with greater than 500 shared folders—a restrict eliminated in 2019. Nonetheless, Redmond now believes the difficulty additionally impacts customers with an analogous variety of folders of their major mailbox.
Microsoft says customers attempting to ship emails from the Outlook desktop app could obtain an surprising Non-Supply Report (NDR) with the 0x80040305 error code.
“This subject is just like the prior 500 folder restrict that the Outlook Staff mounted, Lifting the five hundred Folder Restrict in Outlook,” the corporate mentioned. “That answer focused shared folders however didn’t embody the situation occurring within the consumer’s major mailbox.”
Affected customers can even be notified that their emails didn’t attain “some or all” recipients, with the NDR message advising them to resend it later or contact their community administrator.
The Outlook Staff has developed a repair for this downside, which will probably be rolled out to the next launch channels later this month or in December:
- Beta Channel: Model 2410 (Construct 18127.15020), anticipated early October 2024
- Present Channel Preview: Model 2410 (Construct 18129.20000), anticipated October 9, 2024
- Present Channel: Model 2410 (Construct 18129.20000), anticipated October 29, 2024
- Month-to-month Enterprise Channel: Model 2410 (Construct 18129.20000), anticipated December 10, 2024
Workaround additionally accessible
Within the meantime, till the affected customers’ software program is mounted, Microsoft gives a brief workaround requiring them to cut back the variety of folders with subfolders to beneath 500, aiming for 450 nested folders.
One other momentary answer to those Outlook email-sending issues is to maintain all mailbox folders collapsed slightly than expanded.
“If you cannot do both of the above, keep away from subsequent on-line actions in Outlook. Such actions embody utilizing the buttons for ‘View on Server’ and ‘Click on right here to view extra on Microsoft Trade,’ or use of ‘Embrace older outcomes’ when looking,” Microsoft mentioned.
“When you use any of those actions, restart Outlook instantly for finest efficiency.”
Earlier this month, the corporate additionally addressed a bug inflicting Microsoft 365 apps like Outlook, Phrase, Excel, and OneNote to crash whereas typing or spell-checking a textual content.
In August, Microsoft additionally shared momentary workarounds for recognized points triggering Gmail sign-in points for traditional Outlook customers and inflicting Outlook to crash after opening.