When the mail is fetch using POP3, the mail count shown is different than what is shown by the browser

I have been assigned to make a mail client which access the mail from POP3 of Yahoo server. By spending some days, I have successfully made the mail client. My application is correctly fetching the mails from POP3 serve开发者_StackOverflowr and it is sending the mail to the SMTP server.

The problem is; the application can only fetch the mails which are having the recieved date within 60 ~ 70 days (I am not sure about the day count).

When I checked the account in the browser, I can see all the mails, but when I fetched the mail from my mail client it is only retrieving the mails which were received within 60 ~70 days of period.

Also, When I used OpenSSL to check the mails, the mail count shown by using openSSL client is same as what of my application is fetching.

I wanted to know whether it is a behavior of Yahoo!Pop3 or it is same in case of all other mail service providers. It would be a great help if someone can provide me the URL reference which shows that one can not retrieve the mail from POP3 when the received date of mail is before 60 ~ 90 days (or whatever limit it is).

I am not sure Yahoo! POP3 servers support it, but you might try to check the EXPIRE capability. It tells you for how long the POP3 server will keep the emails.

No-where is it specified for how long a general POP3 server will keep messages. Gmail by default deletes them from all future POP3 session when a mail has been fetched - but the mail is still available using a browser session. Another server I am using never deletes the messages (and are available for infinite days).