Are there any negatives side effects to using PGP all the time with email?
More specifically, if I was to attach my public key to every email — even when the recipient doesn’t use PGP.
My assumption is that “life would carry on” and there would be basically no difference but I’m not entirely sure.
the process of using PGP for encrypting content (text messages for example) is something I’m only just started understanding after some reading and practicing
Your messages won't work right in some Office365 servers that inject the "this email came from outside of your organisation" banner into the body. Oh, and people who get notifications about your email will only see the PGP header string.
Other than that, I don't see the problem. Just make sure not to sign any emails that you don't mind being used against you in court, because PGP accidentally makes it possible to prove your laptop was used to send your messages.
On the plus side, the 12 people you'll ever meet that also use PGP will send you encrypted emails. Just make sure you keep those old, expired keys around, or you won't be able to read your old emails back.
Signing every message should have zero effect for people who don't use PGP; they'll just have a cryptic block of text at the bottom of the message you sent.
It's overkill to ship your pubkey with every email. Most people just publish to a trusted keyserver and call it a day since pretty much every client worth its salt can look up your pubkey directly.
Please tell me clients handle everything automatically/on the fly...I recently read a comment making a "joke" about the hassle of needing to manually decrypt/encrypt and the tradeoffs of security...and I can't tell if it was real
One thing I can think of is an overzealous corporate security solution blocking or holding back your email purely for having an attachment, or because it misunderstands/presumes the cipher-looking text file to be an attempt to bypass filtering.
Other than that might be curious questions from curious receivers of the key/file they may not understand, and will not be expecting. (“What’s this for? Is this part of the contract documents? Oh well, I’ll forward it to the client anyway”)
Other than that it’s a public key, go for it. Hard (for me anyway) to decide to post them to public keychains when the bot-nets read them for spam, so this might be the next best thing?