Standard Shared Hosting: POP Checking Limits
Are there any limits on often I can check my email via POP?
In order to protect our servers from excessive use that may impact performance, we limit each user to checking their POP email no more frequently than once every 30 seconds. This limit does not affect use of IMAP, SMTP, or WebMail.
We take an average of your connection frequency over the period of an hour. If you are exceeding the rate of once every 30 seconds for an few hours, POP connectivity will be temporarily suspended for 15 minutes to 1 hour — until your hourly average rate of successful connections falls back to at most once every 30 seconds.
Most clients find that once every 3-5 minutes is frequent enough for checking their POP email, as email is not an instantaneous medium.