Men please i need some help in sending invitation emails because it shows all emails sent but wen i open the gmail i cant find any email sent some help please

Have a look around in the forum, there are many posts about the topic sending emails.

There can be a lot of different reasons why your emails are not sent or often it is more that they are not received.

So, how did you configure Limesurvey to send emails?
What type of email service do you use?

Holch man am using PHP to send email but funny enough wen i switch the survey to public registration it sends the email but wat i want is in the email invitation and reminder

Well, the PHP method it the least desireabele. Here a few reasons:
- PHP sending might have limits on your server (amount of emails to be send per hour/minute), often hosters block it completely.
- Emails sent via PHP are very often blocked from mail servers, because they are often used for spam.

However, if the email is sent for the public registration, then this can't be the problem. But I haven't heard from any general problems sending emails in 2.57.

So should i upgrade to the other version Holtch??

If there is another, newer version available I would upgrade. Then see if the problem persists. If it persists, make a bug report.