Well whether you have a good password or not, if you lose your smartphone and make use of your email on your mobile, whoever steals your phone can find out all your login details pretty easily if they really wanted to.
Most people have automatic login on their email on their phone which means whoever has access to your phone, has access to you mails. Most logins I forget, usually just require a username and email address to reset it or to get it sent to you. The username would have been sent to your email when you first registered. So all the info should be available to the criminal.
Sites which are important usually requires a cell number as well, like the banks etc. The dude with your phone also have that...if your bank stuff like statements also go to your email then account numbers and adresses are there to be found as well.
Because of the above I dont use my mobile email adress for important stuff. And don't link my phone directly with my work email. Whoever steals my phone will have to steal my laptop too, or have to somehow get access to my work email.
