@B92 I was also distressed to find they had removed this, as I do have to email a guest a hand-drawn map to my place or they'll never find it. But the fact is that half the time the guests told me they received my email, but the attachment wasn't there. So it was glitchy anyway. In those cases, I had to ask the guest for their personal email address, explaining why, and at the same time, giving them mine (I have one email address I use for personal correspondence and one I use for business). I never had a guest balk at this when they understood the reason.
I don't find it extra work, because I message my guests anyway, and just include it in a message. I do send them an Airbnb message to let them know when I've sent it, so they can look for it, and tell them to also check their Spam box if they don't find it in their Inbox. I also ask them to confirm that they got it.
It is now possible, supposedly, to add attachments to Airbnb messages, but I've not had an opportunity to check it out, as I home share and haven't been able to host since March, due to COVID.
@Emiel1 What's the difference, re a virus in an attachment, if it's an attachment to an Airbnb message, to a guest's personal email, or to the coded email address that used to be available?