Tips for sending to your email lists without getting your IP blacklisted.
Mailing lists can be a valuable tool for keeping your customers up to date with what is going on with your business. If not used properly however, they can be detrimental to a business's ability to communicate with email. Below are some tips for maintaining a good IP reputation and ensuring your business communications get through.
Verify that everyone you are sending to wants to get your email.
In general, everyone on your email lists should have provided their email address to you for the purpose of business communication. When email addresses are freely provided by the customer, they will expect to get communication from you; they know what they are signing up for. You should be safe sending to these “Opt in” email lists.
Never purchase email lists.
Regardless of what the vendor of those lists tells you, a purchased list is not an “opt-in” list and can harm the sending IP reputation. Just because a customer has “Opted in” to another vendor’s list, that doesn't give the owner of that list to sell it, nor you the right to email to it.
Use a third party service for mass mailing marketing campaigns.
In general, when attempting to market your business, the best way to protect your day-to-day business communication is to use a third party when sending marketing emails.
Companies like Yahoo and Gmail have user-based spam filters. If enough users on their system mark your email as Spam, the system as a whole will not allow you to send to it and your server IP will be blacklisted. For this reason, you are much better off using a third party to send marketing and sales materials.
Warm up your IP slowly.
If you plan on sending out mass communications, like a monthly newsletter or a monthly billing statements to all of your customers, break them up into smaller “bursts” when first sending out this type of communication. Network spam filtering software will look at the amount of mail being sent from an IP address. An IP address that has a huge increase in sent mail from one day to the next can get flagged as being either potentially compromised, or intentionally spamming, and can get you blacklisted.
While there is no magic number for warming up an IP, there are some guidelines out there. We’ve taken the liberty of providing the following “general recommendations” on warming up and IP’s, but please remember that these values are not set in stone and may or may not have the intended result:
Warmup Age (Days) Hourly Email Limit
If you follow this warm up plan you should be able to send to larger lists within 15 days.
Please also keep in mind that these recommendations are per-IP, not per-domain. So if you have multiple domains sharing the same server IP, the total volume from all domains needs to be considered.
Stay CAN SPAM Act compliant.
Your server is based in the US and requires you to be in compliance with US law. In general, as long as your customers have provided their email to you, and you are sending to those addresses for business communication, they should qualify as an “Opt-In” list. Marketing emails should have the physical address of the company and a link to opt-out instructions to stay compliant.
Ensure your server is set up appropriately.
DKIM and SPF records should be assigned for all of our customers by default to ensure optimal email delivery. If you have domains using another provider for DNS services, it is HIGHLY recommended that these records be added immediately for all email volumes.
Monitor the “health” of your IP and domain.
We have automated monitoring internally that checks client IPs for blacklisting, but as new blacklists are always possible, it is important for clients to be able to monitor their IP and domain health as well. There are many third party services and tools that may be used to check for blacklists or other problems on your server’s IPs, domain names, or even individual mailboxes. The following list is not a conclusive list of tools, nor are they perfect for every situation. They are, however, a list of tools that we have found useful over the years and can be used to identify a potential problem before it gets out of hand.
Note: These tools are especially important while warming up a server IP for mass email.
If you do find any issues with your IPs and/or domains, please let us know as soon as possible. As an ISP and the owner of the IP, we have additional methods for mitigating IP reputation issues that you, as the end user of the IP, do not.