In Outlook 2013 and Outlook 2016, you can create personalized signatures for your email messages that include text, images, your electronic business card, a logo, or even an image of your handwritten signature. You can set it up so that signatures can be added automatically to all outgoing messages, or you can choose which messages include a signature.
Add and set up a custom email signature to appear automatically in every email you send
Open your custom HTML signature in browser
Copy the entire signature press ctrl+A then ctrl+C
In Outlook Home tab, choose New Email.
On the Message tab, in the Include group, choose Signature > Signatures.
Under Select signature to edit, choose New, and in the New Signature dialog box, type a name for the signature.
Under Choose default signature, do the following:
In the E-mail account list, choose an email account to associate with the signature.
In the New messages list, choose the signature that you want to be added automatically to all new email messages. If you don’t want to auto sign your email messages, accept the default option of (none).
In the Replies/forwards list, choose the signature that you want to be added automatically (auto sign) when you reply to or forward messages. Otherwise, accept the default option of (none).
Under Edit signature, paste your signature press ctrl+P, and then choose OK.
Use more than one signature
There are options available if you don’t want to have the same signature appear automatically in every email message. You can modify the settings for the current default signature and not use it to auto sign your email messages. The alternative is to manually insert the signature in an email message. Or you can leave the settings for the current default signature in place and remove a signature from an open message. You also can create another signature to use as needed in your email messages.
To insert a signature manually, on the Insert tab, choose Signature, and then choose the signature you want to appear in the message.
To remove a signature from an open message, select the signature in the message body and press Delete.