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As of 9 November 2025 I cannot send emails from my Bigpond.com email account whilst using Microsoft 365 Outlook Classic on my laptop (Windows 10) nor my desktop (Windows 11). I can receive emails though.
For a while I also could not send emails from my Bigpond.com email account from my Android phone whilst using Outlook mobile app but this has now been fixed..
This problem also occurred in October last year but was resolved a few weeks later.
Using Classic Outlook on Windows for personal email, calendar, and contact management
I don't believe it.
Today (18 November) the problem has come back again.
i.e. again I am unable to send emails from my bigpond.com email account whilst using Microsoft 365 Outlook Classic or whilst using the Outlook mobile app for Android.
Don.t understand what is going on.
The problem has gone away again. Today 19 Nov I find I can again send emails from my bigpond.com email account whilst using Microsoft 365 Outlook Classic or whilst using the Outlook mobile app for Android.
Hello, welcome to the Microsoft Q&A forum.
Please create a new profile in Outlook, log in to your email account in the new profile, and then delete the old profile. See if sending emails from the new profile is successful.
These are my thoughts and suggestions; I hope they are helpful.
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Thanks for your suggestion but it does not solve the issue (same situation as last year).
This is the error reported when trying to send email from the M365 Outlook Classic application:
"Task '******@bigpond.com - Sending' reported error (0x800CCC69) : ' The server responded: 550 5.7.1 e{b4cfa745-1907-4878-ad5a-72f64e7d333b}' "
I had the issue twice last year - The first time I interacted with a Microsoft Support person (19 April 2024 - support request number [Moderator note: personal info removed]).
He was not able to get Outlook Classic working. However not long after this it started working correctly again.
The problem re-occurred in September/October 2024 and then started working correctly shortly after.
The problem must be associated with the Outlook Classic application and the Outlook mobile app for Android.
This is a summary of the issue:
I am unable to send emails from my bigpond.com email account whilst using Microsoft 365 Outlook Classic or whilst using the Outlook mobile app for Android.
I am able to receive emails into my bigpond.com email account whilst using Microsoft 365 Outlook Classic or whilst using the Outlook mobile app for Android
I am able to send emails from my bigpond.com email account whilst using Microsoft 365 Outlook New.
I also tried the Repair option via Account Settings \ Email Accounts, and I get the following error:
"The outgoing (SMTP) server does not recognize your account. Please check your email address and try again"
How can you have 3 Microsoft Outlook apps where one has no problem but the other 2 do?
Details of Outlook versions as of today 11 November 2025 below.
Microsoft 365 Outlook Classic - Microsoft® Outlook® for Microsoft 365 MSO (Version 2510 Build 16.0.19328.20178) 64-bit
Outlook Mobile - Version 5.2543.1 (42543823)
I am just hoping a future software update will fix the problem like last time.
Thx
Regards
[Moderator note: personal info removed] Rundell
Update on my situation.
On Thursday 13 November Outlook Classic was working properly again i.e. was sending emails out again whilst using my bigpond email account. I did not do anything. Same scenario as the previous occurrences of problem last year. I assume there must have been some automatic software or configuration update made that fixed the problem.