Gmail has finally released a long-awaited function for creating a signature in rich text format.
Click the image to see it bigger. Ignore that it's in German. That's a quirk of mine.
This screen is in Settings in Gmail (which you can reach by clicking the link in the top right corner). The box where my signature is is where you paste in or craft your own signature, and the rich-text icons allow you to control and customize font styles, colors, sizes, and alignment, or to add lists, links, and images.
So that should be easier, all around! I just pasted my previous HTML signature into the rich-text box, and it transferred perfectly. You could also build one from scratch, and you can include URLs and images as you wish, so you can link to your website or social media pages and include an avatar or business logo.
You can even have a different signature for each reply-to address, so if you wanted to have a personal signature and a business signature, that's possible. Or if you run separate businesses (such as a blog and a store), you might have one signature that goes to readers and one that goes to customers. As an author, you could include an image of your book cover and a link to the Amazon buying page.
There's really no downside to having a simple but effective signature. I encourage you to take advantage of the signature function, and personalize the emails your readers receive. Thanks to Gmail for realizing rich-text was the next (overdue) step forward!