But what exactly is email warm-up and is it the only answer to your deliverability problems?
What is email warm-up and should I use it?
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What is Email Warm-Up?
When it comes to email marketing , the phrase “email warm-up” may sound a little peculiar, but it’s a crucial process for anyone serious about reaching their audience’s inboxes. Essentially, email warm-up involves gradually singapore number increasing the volume of emails sent from a new or inactive email account.

This measured approach builds trust with Internet Service Providers (ISPs) like Gmail, Yahoo, and Outlook, proving that your emails are legitimate and valuable to recipients. Think of it like showing up to the neighborhood watch before hosting a big party—you want to be recognized as a friendly face, not a potential nuisance.
Mechanics of email warm-up
The process typically begins with sending a small number of email messages to a highly engaged segment of your list or even your own personal accounts. These initial emails should prioritize quality over quantity, with compelling subject lines and valuable content that encourages opens, clicks, and responses. These positive interactions signal to ISPs that their messages are well-received by recipients.
As you continue to send emails and receive a positive response, you can gradually increase the volume, expanding your reach to a broader audience. The key is to maintain a consistent schedule and closely monitor engagement metrics. If you see a drop in open rates or an increase in spam complaints, that's a sign you need to slow down and reevaluate your strategy.
While the process can be done manually, there are several email warm-up tools and services, such as Pribox, that can automate and streamline the process. These tools can help you create warm-up schedules, send automated emails , and track their progress, making it easier to establish a positive sender reputation and improve your email deliverability.
Why is warm-up email used? The fundamental role of sender reputation
When it comes to email deliverability , sender reputation matters the most. It’s the digital equivalent of a credit score, influencing whether your emails are welcomed into the inbox or banished to the spam folder. Internet service providers (ISPs) like Gmail, Yahoo, and Outlook act as watchful gatekeepers, employing sophisticated algorithms to assess the trustworthiness of incoming emails.
Sender reputation factors
ISPs use complex algorithms to filter incoming emails, separating legitimate messages from spam . New or inactive accounts that lack a history of positive interactions are often viewed with suspicion, and their emails are more likely to be flagged as spam. By warming up your email account, you're essentially building a positive history, proving to ISPs that you're a trustworthy sender.
Think of it this way: If you suddenly received a hundred emails from a stranger, you would probably be hesitant to open them. But if you've been receiving a few emails a week from that same person, and they've consistently provided you with valuable information or interesting content, you're much more likely to trust their messages and open them without hesitation.
More than 80% of email traffic is spam.
69 % of email recipients report marking emails as spam based solely on the subject line or sender name.
It is estimated that businesses lose around $20.5 billion annually due to poor email deliverability.
Email warming can increase inbox placement rates by up to 30%.
What factors go into sender reputation? ISPs take into account several factors when evaluating sender reputation. Sending volume is a crucial element; a sudden increase in emails from a new or inactive account can set off alarm bells and signal potential spam activity . Engagement rates, including open, click, and reply rates, also play an important role. High engagement indicates that recipients find your emails valuable and relevant, which improves your reputation. Conversely, spam complaints and high bounce rates (emails that don’t reach the recipient) can seriously damage your reputation.