On May 30th of 2024 the attorney representing the defend[ant] [sent] me a threaten[ing] letter
Threatening you about what? What was threatening about it?
on June 28th of 2024 I filed a lawsuit against said contents
What does "a lawsuit against said contents" mean? Are you represented by an attorney in this lawsuit? I'm guessing not.
the summons was served and received by the attorney on July 3rd of 2024
"Served and received by the attorney"? I think what you're saying is that you attempted to effect service on the defendant by delivering the summons and complaint to the defendant's attorney. Correct?
Now June 16th of 2024 the attorney sent me a vague letter stating they do not have authority to accept summons and complaint on behalf of the defendant.
I assume "June" is a typo and that you meant "July 16." Correct? Is the letter dated 7/16/24, or does it have an earlier date, but you received it today?
How is the letter vague?
My question is,
1. what are some of the reasons why this attorney waited until now the state this?
Possible reasons include the following:
1. The attorney had better things to do.
2. The attorney wanted to mess with you.
3. The attorney is lazy.
4. The attorney was on vacation.
5. The attorney was in trial on other matters.
6. There are dozens - maybe even hundreds - of other possible reasons.
Rather obviously, no one here has any insight into why this unknown attorney waited 13 days to send you the letter. More importantly, who cares? The reason(s) for the 13-day "delay" are utterly irrelevant to anything.
I should not have to reserve another summons to the defendant, do I?
Unless the attorney agreed in advance to accept service on behalf of his/her client, your delivery of the summons and complaint to the attorney was not valid under
Rule 1-004 of the New Mexico Rules of Civil Procedure.
I'm guessing you're attempting to handle a lawsuit without an attorney. If you're going to do that, you need to familiarize yourself with the Rules of Civil Procedure. If you fail to do that, you're very likely to lose your case for reasons having nothing to do with the merits of the case.