Copper
What Copper's own documentation says about sending email with Microsoft 365, why Copper has no Microsoft 365 connection to sign, and how to get Footer365's signature on email you write in Outlook.
Copper's documentation describes no way to send email through a Microsoft 365 mailbox, so there is no mailbox connection for Footer365 to sign. Choose how your CRM or app sends its mail explains the two ways to send and why.
At a glance
- Can be signed: email you write in Outlook, as any Outlook mail. Copper says: "If you use a different email client, like Outlook, you can instead select 'email links open in my default email client'".
- Cannot be signed: email sent with Copper's Send and reply from Copper setting. Copper says: "You must have the Gmail sync set up in Copper to use the 'Send and reply from Copper' email setting." It does not mention Microsoft 365 or Office 365.
- Status: from Copper's documentation as read on 23 October 2026, not tested by Footer365. The page is dated 19 March 2025.
What you can do
- In Copper, choose the setting that opens your default email client, as Copper describes, so that the email is written in Outlook.
- Make sure each person has a Footer365 signature rule, and that your organisation has mail flow set up or the Outlook add-in deployed. Footer365 then signs the email like any other written in Outlook. Which messages get a signature
- Send a test message, and check one message as described in Mail from your CRM and other apps.
What is not signed
Email sent from within Copper, because Copper's pages read describe it only for Gmail. Footer365 never sees mail sent from Copper's own servers. A connector into Exchange Online is not an option: Microsoft says SMTP relay cannot be used for a service hosted by someone else. Last resort: a connector to Exchange Online
If it does not work
- The email opens in the wrong program. Check the setting in Copper and your computer's default email program.
- The message has no
X-Footer365-Relay-Id. It did not pass through Microsoft 365 with Footer365. Mail from our CRM is not signed - It passed through Footer365 but is unsigned. The signature was not added
Sources
Read on 23 October 2026:
- Copper: Send and reply from Copper setting, 19 March 2025.
Still stuck?
Tell us what you were trying to do and what you saw. Include the sender, a recipient and roughly when a message was sent, and we can trace it.