Outlook email "groups" have suddenly disappeared; contacts still there but no groups.

I'm surprised to see this re-emergence of the "disappearing groups" problem. After my outlook.com account was migrated to the new version mid 2016, things have been very stable. I will say that I am using Microsoft Office 2016 Outlook to actually manage the groups, rather than the web application, and this also gives me the safety net of saving a backup. If I was using my outlook.com for business or more critical applications, I'd certainly go that way, or one step further into the professional version of Office 365.

However, my biggest distro group of about 120 addresses has behaved well. There are a couple of anomalies which relate to some of the recent posts... If someone has a change of email address, and I change it in Office Outlook, that change is mirrored to outlook.com BUT I need to remove that contact from the group, and re-insert it with the new address. I noted also that when updating a contact's email (again in Office Outlook), it pays to click on the dropdown on the email line to see whether the contact has more than one email address. On at least one occasion, this explained the old address "persisting" when it should have disappeared.

Not sure, InkmastersCairns, what you mean by not being able to send to multiple addresses. You can do this by your groups/lists, and by simply adding more addresses in the To: line in the web client. The cursor goes to the right of any previous address you inserted, and usually typing the first couple of letters of the name will do the trick. Alternatively (again in web Outlook), in the People page, you can check the boxes that appear left of the person's name when you hover mouse over it, and when you have checked all the ones you want, you'll see that an icon has appeared on the right pane, with a "Send email" option to the selected addresses.

I do think, though, that for people who only use the web based outlook.com client, there should be a better and more obvious way to export/save/backup your groups/lists. Come on, MS! Fix this!

I agree with all the other people who are complaining - I have tried everything suggested. We have lost the lists twice but not addressees. It has not happened again for some time now, fingers crossed. Microsoft email is a dud on other fronts as well - can't send to multiple addresses, will NOT edit some email addresses and sends to the old one even though the new email is listed on the person's page. What is that???

And I agree regarding everyone's comments on solutions, none have worked. Have to bite the bullet and go elsewhere. Does anyone have any suggestions please?  We have around 900 addressees, multiple lists and it is accessed daily by several people.

2nd time in 6 months, ad enough, i will be cancelling my subscription, i can't run my business on Ms in consistency

Sorry I could not help.  Good luck

Thanks very much, you do a wonderful job and must save many people from completely losing it.