Can't access webmail - keep getting message about downloading appsuite

I've stopped being able to send emails from my email client, both on desktop and phone. In an unsuccessful attempt to fix that, and following instructions from VirginMedia support, I changed the settings on the server, added a password etc, and the main effect of that has been that on my phone I can no longer either send or receive emails.

I thought never mind, at least I can access my email via webmail. I have been doing that successfully on my desktop but when I try to do it on my phone, I get a message telling me that Appsuite is downloading. Appsuite never finishes downloading, and it is impossible to stop it. Every time I try to refresh and just log into webmail, it tells me that doing this will interrupt the download.

I see other people on this forum have had the same problem and the suggested solution has been to delete the cache and the cookies from the phone. I've done this, but it hasn't worked. This is particularly troublesome for me because I use email for work. I am about to go on jury service for two weeks and need to be able to access email on my phone.

Any suggestions gratefully received.