Signature synchronization between Outlook Desktop and Web Client

Teresa_Cyrus, sbarry019 

Perhaps this has changed in the few months since the exchange above, but you definitely do NOT need to use the new Outlook as of Summer 2023 (and I think even as of 2022, but maybe I had a more recent version of Outlook). In the current iteration of Outlook, that "Try the new Outlook" switch launches a completely different beast that is pretty much just the web app. I find it unusable due to all the missing and broken features compared to the conventional desktop Outlook, which is still being updated in parallel. Maybe one day it will be better, but it's not there yet.

Meanwhile, to sync signatures between Outlook for the desktop and the cloud, you need to either edit the signature in Outlook for the tenant in question:

1. From Options or an email message composition window, select Signatures.
2. In the dropdown for "E-mail account" select your tenant account (where it says, "Signatures on this device" in the screen shot):
   
3. Paste your signature in the Edit box or create it (pasting it from Outlook gives a lot more editing options, including using a table to properly format and position pictures so they look good, not just in Outlook but for gmail and other webmail users). 
4. Hit OK
5. Wait. It can take time (minutes to hours) to sync
6. Check if it's uploaded in your online interface: https://outlook.office.com/mail/options/mail/messageContent

Once it's there, it will also download to all copies of desktop Outlook. You just need a version late enough to include the "E-mail account" drop-down shown in the screen shot above.

OR, create the signature at https://outlook.office.com/mail/options/mail/messageContent and then it will similarly sync to Outlook, but the online editor is really terrible for precise positioning that will work on various clients. I recommend using the one in desktop Outlook.

Whatever you do, after you've created it, be sure to test send to lots of different kinds of accounts, because a sig that looks perfect in Outlook might look terrible in Gmail, or look decent in both of those but fail in Thunderbird, etc. Generally, a table is the best way to ensure some level of formatting consistency across platforms.