Copy your signature first, then pick your app and follow the steps. Paste with Ctrl+V on Windows or Cmd+V on a Mac. Do not use paste without formatting.
Gmail
Outlook web
Outlook desktop
Apple Mail
Open Gmail, click the gear icon at the top right, then See all settings .
On the General tab, scroll to Signature and click Create new .
Name it, click in the signature box, and paste.
Under Signature defaults , choose it for new emails and for replies.
Scroll to the bottom and click Save changes .
Gmail strips embedded style rules, so dark mode there relies on Gmail's automatic color inversion. The signature's off-black and mid-gray text inverts cleanly without distorting the greens.
Click the gear icon at the top right, then choose Mail and Compose and reply .
Under Email signature , click New signature and give it a name.
Click in the editing box and paste.
Set it as the default for new messages and for replies and forwards.
Click Save .
Windows
Go to File , then Options , then Mail , and click Signatures .
Click New , name the signature, click in the editing box, and paste.
Under Choose default signature , pick it for new messages and replies.
Click OK .
Mac
Go to Outlook in the menu bar, then Settings , then Signatures .
Click the + button, name the signature, and paste into the editing box.
A small clipboard icon appears next to the pasted content. Click it and choose Keep source formatting . Skipping this step strips the colors and logo.
Under Choose default signature , pick it for new messages and replies, then close the window.
Open Mail, go to Mail in the menu bar, then Settings , then Signatures .
Select your school account in the left column and click the + button.
Before pasting, uncheck "Always match my default message font." This step is required. If it is still checked when you paste, Mail throws away the signature styling and colors.
Name the signature, click in the right pane, and paste.
Close the window. The signature saves automatically.
Apple Mail honors the signature's embedded dark mode rules. On a dark background the green links brighten to Spring Green so they stay readable.