What can happen to emails if an incorrect SMTP configuration exists?

When SMTP configuration is incorrect, the most immediate consequence is that emails may bounce back or fail to send. The Simple Mail Transfer Protocol (SMTP) is essential for the transmission of emails over the internet, and any misconfiguration in settings such as server addresses, ports, authentication methods, or security protocols can disrupt the email delivery process.

If the configuration has issues, the email server may not be able to locate the recipient's server or communicate effectively with it, resulting in a failure to deliver the email. In many cases, the sender will receive a bounce-back message indicating that the email could not be delivered due to these issues. This behavior clearly illustrates the importance of having a properly configured SMTP setup to ensure successful emails transmission.

The other options present scenarios that do not align with what typically happens due to an incorrect SMTP setup. For instance, emails being delivered successfully or always being delayed doesn't accurately reflect the direct impact of configuration errors, while automatic storage of emails would typically occur due to server-side settings, rather than SMTP configuration mistakes.