How often can I ping gmail with pop3 requests ?

I have a timer set to check for new messages every 45 seconds… Am I safe or will Gmail block me or does anyone know ?

45 seconds to check for a new message why ?

Would every 5 minutes not be enough.

I switched it to 150 seconds but… basically, I’m checking for paypal transaction ID’s which are then uploaded to a textfile on my server. My program checks this file to confirm transID’s and then sends a notice back to my other program to let it know that, that transID has been used and to mark it used … well anyways…

If I’m my customer lets say… and i buy my program, I get my paypal transID within seconds… so then i open the program and put in the paypal transID to unlock the program and they’ll get an error until that sync process is complete. I’m already letting them know to wait at least 5 minutes… but I’d like to check the server ideally for new messages as often as possible… My question I guess is… am I going to get in trouble blocked ? for counting messages every 20, 30, 40 60 ? 100 150 ? seconds ? what’s the rules ?

[quote=43419:@Christopher Ridgeway]I switched it to 150 seconds but… basically, I’m checking for paypal transaction ID’s which are then uploaded to a textfile on my server. My program checks this file to confirm transID’s and then sends a notice back to my other program to let it know that, that transID has been used and to mark it used … well anyways…

If I’m my customer lets say… and i buy my program, I get my paypal transID within seconds… so then i open the program and put in the paypal transID to unlock the program and they’ll get an error until that sync process is complete. I’m already letting them know to wait at least 5 minutes… but I’d like to check the server ideally for new messages as often as possible… My question I guess is… am I going to get in trouble blocked ? for counting messages every 20, 30, 40 60 ? 100 150 ? seconds ? what’s the rules ?[/quote]

Why not ask Google ?

I’m not an expert in the PayPal SDK, but does it not offer a way to post to a URL on purchase? If so, you could just post to the URL of a Xojo web app and then the web app (using WebApplication.HandleSpecialURL) could update your text file. This wold be instantaneous and not require the use of email at all.

[quote=43455:@Paul Lefebvre]I’m not an expert in the PayPal SDK, but does it not offer a way to post to a URL on purchase? If so, you could just post to the URL of a Xojo web app and then the web app (using WebApplication.HandleSpecialURL) could update your text file. This wold be instantaneous and not require the use of email at all.
[/quote]

Yes it does. And then PayPal knows if you got the order because you stick an acknowledgement in your HTTP(S) reply. With email notification, they don’t know. And you’ll need to periodically scan your orders on their site to see if you missed any.

Look up PayPal IPN (instant payment notifications). They have example code in most languages on their developer site and it’s not hard to implement.

I use them on my site so that when my server receives an IPN from PayPal it assigns a license code and sends it via email to the customer. That way everything is always in sync as the customer doesn’t get a license code until I receive an IPN.

As others have already suggested, PayPal IPN (Instant Payment Notification) is the way to go. You’ll get real-time notifications of all account activity and be expected to acknowledge receipt of each one. Visit https://developer.paypal.com/webapps/developer/docs/classic/products/instant-payment-notification/ to read about it.

In addition to PayPal IPN, you can implement PayPal’s Auto Return for Website Payments with Payment Data Transfer, the latter of which provides payment details. It’s a way to present your buyer with real-time feedback immediately after their purchase. Visit https://developer.paypal.com/webapps/developer/docs/classic/products/payment-data-transfer/ to read about it.

I forgot to mention the major drawback of relying on PayPal email notifications is reliance on a third-party to relay information. That third-party may be slow or worse yet, never deliver the email message. You’re already experiencing a delay. Imagine not receiving an email message at all.

With PayPal IPN and Auto Return for Website Payments with Payment Data Transfer, information is being presented directly to your code in real-time. If you don’t acknowledge receipt of a PayPal IPN, PayPal attempts to resend it until either you do or 4 days have passed.

Since you’ve already implemented a system to process the email messages from PayPal, it may be worth keeping it in place as a backup but the primary means of communicating with PayPal should be IPN. That may or may not be supplemented with Auto Return for Website Payments with Payment Data Transfer.

If the user puts in a transID that you haven’t gotten yet, do an immediate scan of the email, just in case.

You might like to have a look at QuickStart Software’s Paypal and credit card classes that handle IPN, auto return and much more:
quickstartsoftware.com
There is a tutorial screencast available and the classes come with several example projects. I found they save a lot of time.

Sorry, I messed up the link! quickstartsoftware.com