It could be caused by:-

1) You have too many messages in your Inbox, and this is causing your device (eg PC/Mac/iPhone/iPad/Android) to load the Inbox slowly

2) A problem with your internet connection (eg it being slow / wireless router poorly located / etc)

3) A problem with your computer

1) Check how many messages you have in your Inbox. If you have thousands (or tens of thousands) then we'd recommend archiving messages into folders.
eg have a folder called "Archive 2019", "Archive 2018", "Archive 2017" etc and leave your inbox with a few hundred messages or less in it. If you log a support ticket with us we can archive your messages for you and re-create your indexes to speed things up

2) If you don't have lots of messages in your Inbox, then:-

a) If you access your email using software like "Mail" or "Thunderbird" on a Mac, or "Windows Mail", "Windows Live Mail" or "Outlook" on a PC, then try checking your emails by logging in at www.ph9mail.co.uk. There should be no delay there as you're accessing the emails from the source

b) Make sure your internet connection is running reliably and fast. To check this, do a speed test at www.speedtest.net - anything slower than 20mb download or 5mb upload would mean your internet connection is running slowly. To give you an idea, a "fast" internet connection would be 200mb download and 20mb upload.

c) Reboot your device (complete power off and power on)

d) If your emails are busy synchronizing, or you've literally just set up your email account on this device, then you may simply need to wait for the messages to synchronize.

e) Sometimes if your messages are downloading slowly its because your mail program or device is busy doing something else, and that is chewing your internet connection up and slowing everything down