A name belongs where its words already live
An exact-match .com is only worth something to the company whose customers would type it without being told. Finding that company is most of the work, and it happens before anyone gets an email.
Start here: who would a customer expect to find at this address?
Three checks before I write
The customer says it
The words in the name are the words people use for what the company sells, in reviews, in searches, on the phone. If only the industry uses them, the name is weaker than it looks.
The company is the natural owner
Its products, its market or its own name line up with the words closely enough that a visitor would not be surprised to land there. Often it already uses a longer or hyphenated version of the same address.
The name is clean
It carries no one else's trademark and has no history that would follow it into your inbox or your search results. If I have doubts, I leave the name alone.
Query to the author: does this read right to your customers?
What the right .com changes
The practical gains are small and daily. Customers who remember what you do but not exactly what you are called still find you. Email written to the address people guess lands in your own inbox instead of someone else's. Printed material, vehicles and radio spots can carry an address that needs no spelling out.
There is also a quieter one: nobody else can use those words as their address and borrow the trust your company built around them.
Keep the words customers already say. Change only the address.
What my note looks like
Short, plain text, no attachments and no links. It names the domain, says in a sentence why I think it fits your company, and asks one question about your plans. Sometimes the answer is that you are rebranding, or that the name matters more to a sister company. That is worth knowing, and I would rather ask than guess.
If you received a note and want the details, reply to it or use the contact page.
One question, then your call.