Hi @jerryw ,
Any of our articles regarding email design best practices would be good places to start. If you're generally just going to be sending a plain-text style email, you should be okay to leave it as a single text block, up to a certain length. However it's generally helpful to split up such emails with some kind of divider or other element for the sake of readability. We've found that people are much more willing to fully read emails that are split into more digestible sections, than one longer essay-style writing. If you're regularly copying copies of copies, then it's possible the email build up junk coding overtime, even if it's a fairly barebones email, such as plain-text email. Generally speaking, it's best to copy from a more original source, like a master/reusable template for each new sendout you're planning to do.
I'd recommend taking a look at some of these articles for additional info on email design:
Designing emails best practices overview (links to other relevant articles)
Create a reusable template
Save a reusable template
... View more
