Hello,
I have a problem on iPad with someone delayed sending mail via secure SMTP when IPAD is connected via wifi?
I have IPAD 3G + WiFi. If I send mail through 3G everything works, when I switch to wifi network mail someone sends to be delay of 2-4 hours. I've done a complete restore, but to no avail.

Thank you

Could it be something with the router ?
Does it happen on other WiFi net - try some public free WiFi.

You should check your mail sync settings.

Go to Settings > Mail, Contacts, Calendars > Fetch New Data and select it.

If your mail service uses IMAP then make sure Push is set to on. Also set a Fetch time that seems right to you. This will set the sync time for mail accounts that don't support push, like a POP account. Even if you don't need it now it will save you from remembering to set it if you add another account later.

Now select the Advanced option. You will see a list of all your accounts and their settings. Change them to Push, Fetch, or Manual as appropriate.