Solved Emails sent from Gmail account using Outlook desktop client to other emails disappear

I have a Gmail account for a walking group I run. I use Outlook (Microsoft 365, version 2511) to send and receive emails to and from that account. Been using it for ages.

Earlier this morning I sent out a report from Thursday's walk to some 49 recipients (first time I've sent from the account this year, previous time was 9th December). As usual I sent it to the account itself and BCC'd it to the 49 recipients including my own and my wife's personal Gmail accounts.

The account received its own copy, but none of the others did, no fail messages, nothing in spam, they've just black-holed.

I haven't changed any settings since last used in December. When I got a new PC last June I set the various Gmail accounts up from scratch and they've worked fine since then.

Tried a couple of test emails from the account on my Android phone using the Gmail app, worked fine. Then sent the original email using Gmail in Chrome on my PC and that's worked.

Also done an experiment with all 3 of the Gmail accounts we have - call them A1, A2, A3:
- From A1 to A1, A2 & A3 - all received ok.
- From A2 to A1, A2 & A3 - all received ok.
- From A3 to A1, A2 & A3 - only A3 received the email. A3 is the walking group account.

I've compare the Outlook parameters for the 3 accounts - all the same (apart from address and password)
I've compared the Google account details for the accounts, can see no difference.

It would seem something has changed in the past 2 or 3 weeks in the relationship between Outlook and Gmail. Perhaps new in 2026?

Thoughts welcome please.

I just tried what you did, (with only 5 recipients though, and no attachments), worked okay.

Thanks.

It's getting weird. The test emails I sent are dribbling through. But no sign of the original walk report email. System problem somewhere?

tpriest said:

... no sign of the original walk report email. System problem somewhere?

Click to expand...

Is the attachment too large?

Good thought. But no, 3 files totalling 2 Meg.

Thanks for your thoughts but it looks as if there was some sort of problem earlier with Gmail/Outlook or thereabouts. I sent an apology for the repeated email to all and that went through straight away.

Will mark this as resolved.