From what I've read in the comments, the structure of your url is ti_hom.xxxxxx.yyyyy.br
and the problem is just that: internet explorer has problems with urls containing _ ( underscore ) .
Translation of a relevant part of the linked article:
[...] the underscore is an acceptable character in a url [...]
However, IE does not seem to like it when it's part of the name
of the domain or subdomain [...] The problem happens when you need
use cookie on the site, which most sites need,
especially if you are using cookies as part of the
validation. IE can not create cookies when the domain name or
subdomain has an underscore
Unfortunately, it looks like there is no workaround , in addition to renaming of your domain or instruct your users to use the IP address directly / swap browser. All alternatives can be problematic, so it's up to you to decide which path to take.