It's been about fourteen years since I had anything like a service outage with a web host, and that was with PlugSocket... who were subsequently bought out by UnitedHosting (2012) who in turn were bought out by Iomart / EasySpace / HostingUK (2018). And they've been very good on the whole, helping to sort out an SSL cert and getting things upgraded to a modern rather than grandfathered hosting package a few years ago.
Then at the end of the day on 24th April / 25th someone mentioned they'd tried to send me an email and it failed, and I realised I hadn't had any emails since the 21st. Which is very unusual, but things had been busy and I hadn't noticed. Sending from the account worked, but test emails from a work account got errors like this:
Reporting-MTA: dns; merlin.xssl.net
Final-recipient: RFC822; [mailbox]@[personal domain]
Remote-MTA: dns; mx1.spamfiltering.com
X-Supplementary-Info: <mx1.spamfiltering.com #5.0.0 smtp; 550 22.214.171.124 is not allowed to send mail from [work domain]. Please see the SPF record, with scope mfrom, identity [work email address], and ip 126.96.36.199>
See if you can suss out what's going wrong there.
It tallies with the general answer from support. Looking at domains on https://dnslytics.com/ip/188.8.131.52 it's potentially more than a few other customers affected. And a service that for most individuals is of higher importance than a site being available having not been for roughly 72 hours, and not identified and resolved until raised by a customer because it was technically responding but misconfigured.