Hi, I am able to send email when my phone is on WiFi or set to 3G but not on 4G LTE. When checking the settings whilst connected by 4G LTE I get "Unable to connect to email server to verify your account information. No response from server". WebMail works fine on both my S10+ on 4G LTE and Win10/Outlook 2019 on my laptop using IMAP/SMTP on WiFi.
I did have an issue were my home Virgin IP address came up as Blocked on Spamhaus. I connected my S10+ through a hotspot on my laptop and ran Wireshark listening to port 25 for a day and it came up with nothing. I then blocked port 25 on my Asus Mesh System and got the block removed. My Virgin IP has not reappeared on the SpamHaus lists. My 4G IP address does not appear on their lists. I am with Tesco Moble (o2) and have not had these issues in the past.
I'm even more baffled now because having spent the whole afternoon Googling for answers as to why this problem might exist it has now corrected itself without any intervention from me. I can only assume this was a Virgin issue that has been rectified intentionally or otherwise.
A spectacular waste of my time - good job I am a retired IT Manager!!