It is a common misconception that e-mail delivery is instantly completed. E-mail is designed to be sent from Mail Server to Mail Server until it reaches the ultimate destination with no guarantee on how long it will reside at each intermediary stop. Most cases of delayed e-mail are due to slow or overloaded mail servers. E-mail delivery delays are caused by spam, frequency of checking one's e-mail, or other hardware issues. When an e-mail is delayed for a significant amount of time, the best way to check why an e-mail is delayed is to analyse the email header on the delivery delay notification to see where the delay is occurring. Read on to learn how to verify why an e-mail is delayed.
Open a Web browser.
Log in to Gmail.
Open the target e-mail to check the reason for its delayed receipt (or the location or mail server where it is being held).
Select the "Show Original" option on the email.
View the "Email Header."
Review the "Received By" e-mail server to determine the location/I.P. address causing the email delay.
Contact your ISP (Internet Service Provider) and provide the I.P. address of the mail server and inquire on the status of your ISP. Ask if the address has been "blacklisted" from sending e-mail. With ongoing efforts to minimise spam e-mail, legitimate e-mails are prevented or delayed from being forwarded to the desired recipient as part of a precaution.
Test the server. If your ISP cannot provide a satisfactory answer to your inquiry, or you are not patient enough to wait on a response, use an alternate e-mail account (ie yahoo, your work e-mail, msn, etc.) to resend the desired e-mail. This will allow you to determine if your ISP has been inadvertently "blacklisted."
Report the problem. If the email used in step 2 is returned, the recipient is most likely having problems with his e-mail. Use an alternate form of communication to inform the person of the potential issue.
E-mail delays do not occur because a recipients e-mail inbox is full. Every e-mail client has a different means to view message headers. E-mail was not intended to be an instantaneous communications medium. Blacklisting I.P. addresses or e-mail servers occur more commonly now as spam prevention measures are taken by ISPs.