Nice guide! Working with HTML in emails has always been a huge pain, lol.

Curious why you needed to add max-width and max-height CSS properties on the icon links? I’d assume width and height would suffice.

Also, a couple accessibility tips:

1. Add role="presentation" to the <table> elements. This removes the semantic meaning behind the tables as they’re solely being used for layout and not for tabular data.
2. Wrap your social media links with <ul> and <li> elements. This helps to provide greater semantic meaning in that this content actually represents a link list. It also helps to provide a number of items when the list is first encountered, allowing the user to skip past the list if so inclined.

This is good stuff, keep it up! 👍