The disadvantage of using HTML signatures is you can only use these if your Outlook message format type is HTML. It won’t work if you send plain text emails or rich text formats. In fact, you won’t even see the signature listed in the drop-down list. Outlook omits it. Another issue is that these HTML signatures require you to put your CSS code in the .HTM file. Often designers use tables and cells so that the code can get pretty elaborate. And you’ll want to verify any image such as a logo or social media icon is accessible from the internet and not locally stored on your computer.
There are 2 ways you can add your signature file. The first is best if you plan to use it regularly, such as automatically adding the email signature to all new emails. With this method, it will show in your Signature drop-down list.
Before you start, I’d suggest making sure your HTML template file renders properly in the browser. If it doesn’t show correctly in a browser, it will most likely fail in an email. In the example below, I’ve used Google Chrome to open my .htm file.
This will open the apps folder that contains your Microsoft Outlook signatures. Usually, it is the appdata\roaming\microsoft\signatures folder.
Your newly added HTML email signature should show in your Signature drop-down list. You should go to Outlook’s Signatures and Stationery dialog and make sure you’ve assigned this to the proper account and if it should apply to new messages as well as replies and forwards.
Another approach some people take is to insert their HTML file directly into the email. This would be good for one-off scenarios. I wouldn’t want to do this process all the time because it requires more steps. The first process can automatically add them.
This method’s benefit is you can use it for almost any type of HTML file and not just email signatures. And that includes both .htm and .html file extensions. The downside is you have to add in a command that probably doesn’t show on your Quick Access bar.
The command is related to Attach File. Now, that command does exist on the Insert menu when you’re in Email. However, it doesn’t display some sub-commands. In particular, Insert as text.
Your new HTML signature will be inserted into the email.
While using an HTML signature is a nice feature, try not to complicate things with your design unless you love HTML and CSS. To give an example, while the signature I created above may look great as 2 columns with images, it doesn’t work well for people viewing on a mobile phone. You always want to test these items before putting them into production.