Warming up IP address

Review

What is IP warming

IP warm up is a process of gradually weekly increase in the volume of advertising campaign sent out from the new IP address in order to create a positive reputation for the mailing services (AOL, Yahoo, Gmail, etc.).

Quick overview

Internet providers treat e-mails, sent from a new IP address, as suspicious until they are sure the sender has a positive reputation. It takes four to eight weeks (depending on targeting, volume and engagement) for the mailing to reach its maximum deliverability.

It may take longer to warm up the IP address if the recipients of your mailing do not perceive it as the mailing they subscribed to ("opt-in"). Some Internet providers restrict senders by setting limits on the volume of such mailings until the senders develop positive reputation. For example, AOL sets a daily limit for new senders of up to 5,000 messages, and Outlook sets a limit of 20,000 messages for the first week.

To make a good impression on your Internet provider from the start, we recommend that you only send e-mails with relevant information for your recipients.

Focus on warming up your most active subscribers, and then add older segments of your audience to your mailing list as you grow. Older segments should be added to your active segments in batches - 10%-25% at a time - so as not to lower your reputation. Run a repeat advertising campaign to attract or return subscribers to those who subscribed more than six months or a year ago (depending on mailing frequency). Be sure to change the mailing content to try to attract subscribers again.

The goal of the warm-up process is to send an e-mail to subscribers who are least likely to complain and unsubscribe. This includes those who have only recently subscribed to the mailing and constantly open/click links in the mailing content.

The more consistent you are with the volume, frequency, complaint, and bounce rates during the warm-up phase, the faster you'll build a positive sender reputation.

If you send e-mails infrequently (less than once a week) it will take you longer to build a positive sender reputation.

IP warming plan

The path to success

Recommended thresholds

Comments

First week

20,000 messages per day/Internet provider

Excluding: AOL and Yahoo:

AOL: start with 5,000 messages per day and gradually add

Yahoo: start with 40,000 messages per da

During the first and second week of the new mailing, send messages only to the most active subscribers.

Preferably those who were active in the last 30 days before starting the new mailing.

Second week

40,000 messages per day/Internet provider

Excluding: AOL and Yahoo:

AOL: 10,000 messages per day

Yahoo: start with 80,000 messages per day

Third week

80,000 messages per day/Internet provider

Excluding: AOL and Yahoo:

AOL: 20,000 messages per day

Yahoo: start with 160,000 messages per day

During third and fourth week of the mailing, send messages to those subscribers who have been active in the last 60 days.

Fourth week

160,000 messages per day/Internet provider

Excluding: AOL and Yahoo:

AOL: 40,000 messages per day

Yahoo: start with 320,000 messages per day

The volumes shown are just the maximum limits.

But remember; never increase these volumes more than twice as much as last week's mailing when you exceed the first week's limit.

Fifth week (and so on)

Send no more than twice as much messages, as you sent last week/day.

Add segments of your old audience piece by piece, keep a close eye on the statistics, if you start to have problems with your Internet provider, go back to the previous volume of mailing.

During the fifth week, keep the percentage of passive subscribers no higher than 25% of the total volume of messages sent.

You should be able to double that volume each week thereafter.

What to expect:

Once you start warming up your IP addresses, you can expect some increase in volume and blocking. It's important to stick to a plan. Below is detailed information on what you can expect and what actions you should take.

  • Mass mailings to Yahoo, AOL, and Gmail. Usually after a few mailings with positive metrics, things clear up, but it may take time to get the first messages to the inbox. The key is to keep on mailing.

  • Possible blocking by Internet providers can occur if your subscriber list is not active enough or if you exceed the daily limits for each Internet provider listed in the table above. The key is to carefully segment and potentially reduce your current mailing volume to that week's allowed mailing volume, and then start ramping up depending on the Internet provider. Again, the main point is to keep your mailing going.

  • It's important to monitor your metrics and adjust your plan accordingly during the warm-up period.

Why IP warming is so important

Quick warm up

Slow warm up

Internet providers observe spikes in volumes

Internet providers are seeing a slow increase in volumes

Unknown senders

Over time, a positive reputation is formed

Occurrence of blocking/filtering/speed limits

Sometimes blocking/filtering/speed limits occur

IP address warming helps you build a good reputation as a sender

Sender reputation is how recipients perceive you and your e-mail.

E-mail reputation affects deliverability:

  • Bad reputation = Spam or Blocked folder;

  • Good reputation = Inbox.

Reputation of the sender's domain and/or IP address depends on:

  • Spam complaints;

  • Invalid e-mail addresses (hard bounces);

  • Being caught in a spam trap;

  • Authentication (SPF, Sender ID, DKIM, DMARC);

  • Third party blacklists;

  • Engagement.

Your reputation is positively affected by:

  • E-mails openings;

  • Clicking on links in e-mails;

  • Authentication (DKIM, SPF, Sender ID, DMARC).

Your reputation is negatively affected by:

  • Large number of recipient complaints (spam reports);

  • Poor mailing list quality: problematic e-mail addresses;

  • Blacklists of IP-addresses and domains;

  • Getting your e-mails into a spam trap;

  • Large spikes in mailing volume.

Reputation basics

  • Subscribers (opt-ins) are the most important;

  • If people don't want to receive your mail, your reputation suffers;

  • Recipients and metrics are the judge and jury when it comes to mailbox delivery;

  • You can't transfer your reputation from a previously used IP address;

  • If you use the same domain, you can transfer your reputation, but Internet providers, like Gmail, use domain reputation in conjunction with IP address reputation, so you must follow the warm-up process;

  • Internet providers trust their users' metrics and the numbers they observe themselves, so not a single brand gets special preference over others;

  • B2B senders should follow the same warming process as B2C senders, since many business domains are now hosted on Yahoo, Outlook, Gmail, AOL, etc.

Permission and engagement are the most important things

Permission is the cornerstone of building a good sender's reputation.

  • Subscribers complain about mail they don't expect to receive:

    • Are you sending more promotional messages than you promised your subscribers?

    • Are they subscribing to exactly what they're getting?

    • Is the content you send them is different from what you promised them?

Why subscriber engagement is important

Internet providers track how engaged your subscribers are in receiving and reading your e-mail mailing, as well as the nature of that engagement.

  • Positive actions include:

    • Opening the message,

    • adding an e-mail address to contact list,

    • clicking links,

    • clicking to include images button, and reading speed (e.g., scrolling through the message)

  • Negative actions include:

    • Reporting your e-mail messages as spam,

    • Deletion of your e-mail messages,

    • Moving your e-mail messages to the Junk folder, or ignoring them.

  • Engagement rating is another compelling reason to use only opt-in or confirmed opt-in e-mail marketing lists. Subscribing to the mailing maximizes the likelihood of engagement because, theoretically, a relationship has already been established with the recipient.

Remember, quality is always better than quantity.

  • You pay according to the volume of your mailing. If the message never gets opened, that money has been wasted.

  • A lower return on investment (ROI) occurs if you include passive subscribers in your campaigns.

  • Passive subscribers are common cause of complaints, spam traps, hard returns of your mail, which can affect the deliverability/follow-up of your mail in the inbox of active subscribers, which reduces your return on investment (ROI).

  • Run regular re-engagement campaigns to bring back passive subscribers.

  • Send promotional e-mails to passive subscribers less frequently than to active subscribers.

How to keep your mailing list highly engaged

  • Send relevant content to active subscribers.

  • Determine expectations of subscribers from the beginning.

  • Give your subscribers the choice of how often they receive e-mails from you (e.g. once a day, weekly digest, as products become available or go on sale). If you don't send e-mails very often, make that clear. Ask them to whitelist you when they sign up for your newsletter.

  • Implement an onboarding program by telling them about expectations.

  • Try to keep your mailing lists clean, i.e., get rid of non-working e-mail addresses and spam traps.

  • Start by cleaning up your registration forms. If you have the ability to block spam, personal or role-based e-mail addresses, do so.

  • As your mailing lists become obsolete, weed out passive subscribers.

Spam traps

Primary spam traps

E-mail addresses created solely to catch spammers. These e-mail addresses never belong to a real person, don't sign up for e-mail mailings, and certainly never make a purchase. If you fall into these impeccable traps, it's usually an indication that you have a bad data collection partner.

Recycled spam traps

E-mail addresses that once were used by real people, but were abandoned and then recycled by Internet providers into spam traps. Before turning an abandoned e-mail address into a spam trap, Internet providers return an unknown user error code for a period of time (6 to 12 months). If your e-mail message gets caught in a spam trap, it usually indicates that your data hygiene process is not working.

How to avoid and remove spam traps

  • Never buy or rent mailing lists;

  • Eliminate hard bounces;

  • Consistently re-engage passive subscribers;

  • Remove passive subscribers after several unsuccessful attempts to re-engage them.

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