Unprofessional, or Just Very Bold?
This does indeed seem completely unprofessional. Possible explanations are:
They have no clue and don't even realize that it's a bad thing to do,
because nobody ever told them. Maybe it's not even the line of business
they intended to go into.
totally incompetent recruiter
They don't give a damn how rude they are and work by the law of large
numbers. They don't care if they burn bridges or insult people, what
matters are conversions and commissions.
They want to force you to get in touch to avoid this, so that they
can have some time to sell your their pitch for that "awesome new job".
torched-earth tactic (extreme, but plausible)
I'd still call that incompetent, but in their line of business maybe
it's not and it's just a valid technique. your company already sees you
with a foot out the door, so they won't want your environment any more
welcoming. Though that could work to your advantage if they really want
to keep you!
Personal Anecdote and How to Deal with
I've had similar encounters with recruitment agencies. Especially in the UK for some obscure reason. Not all of them, just a few, thankfully (might be due to London's pretty active job market).
They'd actually call my company's switchboard and clearly say they're recruiters and want to talk to me about a new job. Always fun messages to get from the receptionist or from whoever picked up the phone during lunch hour. Especially if you were a recent hire.
Once I also even told them to not call and not annoy my coworkers, and one of them was rude to the receptionist for not putting him through.
I called back and properly yelled at them. Now we blacklist all agencies with unprofessional behaviors when we are the ones hiring. We don't want their business if it's not done right.
I also get lots of emails from recruiters every day and ignore most of them (most are automated or semi-automated spam). But some push the boundaries a bit too far:
- False subject lines with a "RE:" prefix to make you think you were already having a conversation.
- False claims of earlier conversations or recommendations from 3rd parties.
- Overly weird and aggressive tactics that resemble marketing approaches (using urgency to lure you to react, etc...).
I kindly remind them that they're being rude and that it could be seen as unprofessional. If they strike again I contact someone higher up in their company, and generally mark as spam so their emails don't show up again. I'd advise you do the same, if you want to prevent them from bothering other people.
If it's obviously automated crap, then don't even bother replying.