A couple hours ago, I plugged in my iPhone to sync it to my computer.
A series of iTunes dialog boxes appeared, telling me first that it couldn't sync, then that it wasn't capable of syncing (I clicked Override), then that it was missing the right code to do the syncing. And then it synced, apparently successfully.
I was in the middle of other stuff, and everything seemed to be okay, so I figured I would reboot later, and I put it out of my mind.
Not long after that, I did a mail check, and my Comcast mail account failed to check, as sometimes happens. I don't actually use the Comcast account, but they occasionally send me noticed that they consider important.
I tried to send one last email before going to bed, using the Pair relay as usual. (And yes, I do have a valid reason to use the Pair relay instead of my ISP.) It told me it couldn't send.
Usually that means it's been too long since I've checked mail. So I checked mail again.
Sometime around then, Airport Utility suddenly launched itself, for no reason I could see. That was really cryptic and strange, but I figured I must have clicked something that caused it to launch, and that I would reboot later.
Meanwhile, a new message had arrived in my Comcast mailbox. I opened it. It cheerfully informed me that my computer had been sending spam, which meant it was infected with a virus, which meant I needed to run their antivirus software and change some mail configuration settings.
I use a Mac. I'm pretty confident that my computer doesn't have a virus, despite the weird behavior tonight.
But the mail I was trying to send still wouldn't send.
Figured I would reboot. Started quitting a bunch of memory-intensive apps--
And got a kernel panic.
The second one in the past several days.
I rebooted, and everything seems to be fine. But mail still won't send. I looked at various Apple support-forum threads: 1, 2, 3; all seem to suggest that Comcast has automatically changed my outgoing mail port, and that I won't be able to send mail until I tell Mail.app to use the same port that Comcast changed it to. The threads also suggest that Comcast won't have any information about why they did this, nor about how to make it work again, nor will they know anything at all about the Mac.
I'll call Comcast and/or Pair in the morning and see if I can figure out what port settings to use. But in the meantime, I probably won't be able to send mail at all.
I find the whole thing baffling and mysterious. What would have led Comcast's automated system to think I was sending spam? What caused Airport Utility to launch? Is any of this at all related to the iTunes thing or the kernel panics, or is it just a coincidence?
I dunno, and I'm half asleep, so I'm gonna give up for tonight.
Addendum five minutes later: When I went to quit Mail, there was a dialog box offering to let me try "Connection Doctor," so I tried that. It showed me exactly which connections were working (all the mail-checking ones) and which weren't (the outgoing Pair server, plus all the other outgoing ones were slow). Then I found out I could Show Detail to see exactly what traffic was being sent.
So it turns out that (a) Mail.app falls back to port 587 by default if port 25 doesn't work (so I could theoretically send outgoing mail via any of my SMTP servers, it would just be a bit slow if I didn't explicitly tell it to use port 587), and (b) Pair doesn't allow use of port 587. Fortunately, Pair does have a support document saying to use port 2525 if necessary. So I switched to that, and now my outgoing mail via Pair does seem to work.
So, crisis apparently averted. But I'm still wondering why Comcast decided I was spamming, and whether it had anything to do with the mysterious other things going on.
But for now, I'm going to bed.