Although it’s frowned upon by spam fighters, email list verification is still a viable tool to help email marketers with old lists. There are several ways to do email verification, so which method is the best?
Appending verification
The fastest way to do verification is to just mail yourself and collect the data. Unfortunately, you will burn through a ton of IP’s but you will build an entire database of date/time stamp and return path information of each email address. Interspire with PMTA is the most commonly used email platform for appending verification, or at least that is what we hear that most of our clients are using. This is the easiest method if you are a high volume mailer. Collect all the information and any database that you upload to it, append (match and remove) the emails that are no good.
Blank email verification
In order to verify if an email is real or not, you will need to execute an SMTP handshake. Sending a blank email can work but not to top level domains or other sophisticated filters. TLD’s will not accept blank emails so this approach will be very limited to cable emails.
Proxy verification
Proxy hacking can get handshake information about an SMTP server by other means; basically not playing by the rules and going around the basic setups by hacking the server. There are several methods to this madness, which is illegal and not recommended. Stay away from anyone talking about proxy verification.
Snowshoe verification
Distributed handshakes across a huge range of IP addresses many of which are used once. Snowshoe verification is the second most common form of email verification service around. Like snowshoe spamming, the email list verification company will burn through IP’s and domains as they ask many questions from cable and TLD’s.
White listing verification
This email list verification service is the best method and you should ask the verification company if they are doing it this way. White listing is a form of good relationships, whether monetary or not, with internet service providers. You are essentially proving to the internet service providers that your IP’s are safe. Some verification companies slowly warm their IP’s and/or get instant white listing by direct business relationships. This way, you are getting accurate information and not false positives.
Combos
The above five ways of email verification are usually done in combination with each other. Not all ISP’s are willing to whitelist you, let your IP’s in or even allow a blank message for a handshake. The minute they see unusual activity from a range of unrecognizable IP’s, they will immediately block you. Email verification is tough and getting a correct return path is tricky. It’s good to know how the verification companies are doing it if you’re interested in verifying a small list, hook up to a form page, online email address verification API or whatever your needs are.
Original article posted on ehygienics.
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