playgroup e-mailed funny spam - reason for concern?

[GeumBulgaricum]

Earlier today I got an e-mail from the local playgroup with what seemed like a newsletter link. Unfortunately what actually opens has very little to do with playgroups.... I immediately wrote to the playgroup manager and (not sure that was right but still) forwarded it to the local Police. They both replayed immediately:
The playgroup manager: yes spam ive sent nothing
The local police: I’m not sure what this is. Do not intend to open the link as it may well be a virus. I suggest you do the same if you are not sure where this has come from. Does not appear to be any criminal offences unless you can offer any more information.
I guess....
I am not an IT guru to know whether a virus can just get one's e-mail address without any interaction with the website in question, or if a link to 'WTF Candid Conversations about Sex' suggests anything, or if this kind of link is ok from a playgroup to parents with everyone's e-mails in the 'to' line (visible). Puzzling.
What do you recon?

I think spam can be sent with no interaction from email account holder. Mine sends it dodgy links to things a couple of times a year prompting another password change

Their account has obviously been hacked. They just need to change their password. Not really sure why you would forward it to the police? Surely letting the sender know is enough?

My email address sends out spam emails often about sex , viagra, and other over 18 things...
Sometimes to my nieces who are teenagers and to clients.

Very embarrassing

You would need to be able to see the email headers to find out where it came from, the From address is not always the place it really comes from.

Your own computer may be compromised, it could be one of their computers, could be someones computer which gets email from the playgroup especially if the email is sent to a group of people without using a list server (when you get normal mail from the playgroup, can you see it being sent to many people, such as a list of usernames/emails in the To field?)

What to do:
Do not click links in it.
Delete it.
Update anti-virus and run a full system scan.

What mail software are you using? Online systems like Gmail tend to be pretty good at spotting spam.