It seems to be browser related issue.
I suggest you to use another browser like Mozilla Firefox or Google Chrome to login into your email once.
If you don't have these installed on the computer, you can download and install these using the links given below:
If you're facing this issue while using Internet Explorer, I suggest you to reset it once as given under:
Launch Internet explorer
Click Internet Options.
Under the general tab, please delete cookies.
After that click the Advanced tab.
Under Reset Internet Explorer settings, click Reset. Then click Reset again.
When Internet Explorer finishes resetting the settings, click Close in the Reset Internet Explorer Settings dialog box.
Start Internet Explorer again.
If you have any other query regarding this issue, please reply back to me at the box given below.
Please take a second to rate my service by clicking stars at the top of the screen then submit. Bonus/tip is highly appreciated.
Thank you, ***** *****