E-mail verification processes through which email addresses that are supplied by customers of websites are checked in order to confirm their viability for the receipt of the return email. Essentially three checks need to be run on an email address in order to verify its authenticity.

Syntax/format checking is the validation of the characters in which an email address is written. Email addresses that don’t contain the @ symbol are not going to be able to receive the return email from a website, which cuts a potentially lucrative stream of correspondence between sites and customers.

An email address needs to check to confirm the viability of the domain name that is attached to the electronic address. If the domain name does not belong to a bona fide email provider, then the given address will be incapable of receiving return mail.

Mailbox checking allows the pre-@ part of an email to be confirmed as a real electronic mail address. If an email service has ever issued no such mailbox name, then this fact can be established through the implementation of a robust email verification process.

However, Email Verification is not always as simple as this three-stage process would suggest, with different types of email addresses providing different barriers to the successful implementation of a robust email verification process.

Catch-all emails servers are email addresses that are designed to be retained by an email server no matter what mailbox name is supplied before a well-known domain name. The benefits and the downfall of catch-all email verification processes are that they allow every email name, even fake email addresses to be collected within a server. This means that a business can respond to all email addresses whether these are genuine or not, but it also says that catch-all email servers collect a lot of mail that would be rejected through over verification methods. This, in turn, leaves catch-all email servers vulnerable to spam, with no mechanism in place to reject spam from a dubious email address, with the server allowing messages from all address to be received.

When a business looks to market an offer to clients where a catch-all server has been used to collect the email addresses of potential clients it is vital for a business point could well result from invalid email addresses being deleted from the marketing system and with it the potential profits from sales that would have been accrued from the additional marketing output.

Removing invalid email addresses from a list of clients is important for companies who wish to retain customer confidence that could be eroded with the high bounce back rates that will occur if prevalent invalid addresses are not tackled. In order to catch invalid email addresses, companies can look to use features on the command module that exists on Windows and Apple Mac based operating machines. With command produced questioning confirming the status of a web address and confirming whether the located web address is invalid or incorrect. Many companies provide services that locate invalid web addresses from retained catch-all email lists on the internet to assist businesses with this task.