i cannot receive my email on my Iphone

In such a situation, if you're using Apple Mail app and if you're sure (testing on a computer) that your email account is okay and your mail messages are still there, try this workaround:

• Delete your email account on your iPhone (Settings>Mail>Account)
• Restart your iPhone
• Contact your email provider (i.e. gmail, yahoo, aol, hotmail, etc) and check their outgoing/incoming (SMTP/IMAP or POP3) parameters, to be sure you're using the correct info.
• Re-add your email account MANUALLY using the appropriate section in this support article:--> Add an email account to your iPhone, iPad, or iPod touch - Apple Support

Regards

Giulio