IP warming is required when you have been assigned new IP on VPS or Dedicated server. In order to setup a positive sending reputation with global Internet Services Providers, you have to send initially low volume emails from newly assigned IP address. The period can last from day one to up to 60 days. This is the period when your emails newsletters are sent from low delivery to high delivery. It is highly recommended since certain ISP receivers limit senders to thresholds until they build a sender reputation.
Before warming-up your new IP you should first clean your database and then start working on IP warm-up process. And not only clean database you should use, but you should first email to subscribers who often open your email newsletters, remember do not send your email newsletter to a subscriber who often marks you spam or complaint your emails.
During IP warm-up process, you have to manage and maintain the volume, frequency, and complaint, unsubscribe and bounce ratio. If you manage and maintain this ratio correctly, you are guaranteed for establishing a positive sending reputation.
Day one: Send only 200 emails
Day two: Send up to 800 emails
Day three: Send up to 1500 emails
Day four: Send up to 2000 emails
The first week: send not more than 3500 emails per day
The Second Week: Send no more than 10000 emails per day
The Third Week: Send no more than 25000 emails per day
The Fourth Week: Send no more than 100000 emails per day
The second month: Send no more than 500000 emails per day
Some ISPs like Yahoo, AOL and Email will clear up after a few sends with solid positive metrics, but it can take time to get inbox delivery.
Some ISPs like Microsoft and Comcast may delay your emails during warm-up; you may receive 421 bounce remarks and will ask to send email after 72 hours. This delay with such ISPs is normal and will be lessening when IP reputation increases. IP warm-up will also depend upon your list and how many subscribers are opening your email, you should have high open rate and low spam complain and unsubscribe rate and it will impact your reputation while warm-up.
During Warm-Up you have to check following points:
Invalid email addresses (hard bounces)
Authentication (SPF, Sender ID, DKIM, DMARC)
How to Avoid Spam Trap:
Remove disengaged email subscribe who do not open or never open your email.
Do not send emails to rented database list
Do not send emails to purchased database list
Continuously re-engaged your inactive subscribers
Do not send your email to honeypot email IDs and also remember do not send your email to Recycled Spam Traps.
Other points to remember
• Do not send more frequently email newsletter to your subscriber and more frequency will make unsubscribe or spam marking
• Use double option-in form to build your list
• Do not spam wrong content to the audience, engage good content as people will open and read your email periodically.
• Follow CAN-SPAM ACT and CASAL Laws
Bad reputation of IP will deliver your email in Spam or will be black in filter
Good Reputation of IP will give inbox Delivery