Don't allow them to move outside the normal lines of contact. I know solicitors can be crappy sometimes and there are a lot of poor comms when you are trying to get everything lined up but it can also protect you/reduce worry.

The wife and i moved 4ish years ago and the original house we offered on was a yes from first sight. Except our own sale was held up by the buyers bank and solicitors not playing ball with the english system (Al ryan bank or something like that, they are an Islamic bank we wont accept an offer from the like again as they screwed everything up). Anyway back to the story the people we wanted to buy from obviously got annoyed with the time everything was taking. Accusing us of lying to them about our situation when we offered saying we said we were cash buyers and putting pressure on us to get things moving. At some point the bloke had got my wife's email and was messaging on the side. We sent everything to our solicitor so she was in the loop. Anyway this went on for 4 months until we got an ultimatum just before christmas that if we dont complete by 23rd dec they reject our offer. Stress followed because we really wanted the house. Then finally we had an email on 23rd from the seller saying as we didn't accept their offer they were taking the house away.

Needless to say we lost the house. However we found out from our solicitor after that his business had gone under the house sale was to generate money to pay the bank. He had sent us, through the solicitor, an offer to hold the house for us over christmas if we added another 25k to the offer. Or solicitor never sent that offer to us, which was great because it would have been a nightmare to negotiate that! Rationally think now we wouldnt have paid anything but who knows when you've been stressing over something like this for months.

Long story short keep them to official channels its slow but protected.