Are your emails being marked as spam, and as a result, you’re not getting the most from your email marketing campaigns? The answer is probably yes if you have a new SMTP server, IP, and domain. This post will help you learn how to warm up SMTP server IP quickly.
It is a nightmare when emails you send end up in your audience’s spam or promotions folders. Even if all the technical requirements, such as DKIM, SPF, and a perfect 10/10 rating on mail-tester.com, are met, the problem may still arise.

The best thing to do is warm up your new SMTP server IP to start sending emails in bulk. It builds credibility and reputation in the eyes of ISPs and ESPs that deliver your emails.
But what is an SMTP server, anyway? And how does it work? Let’s get to know it first.
What is SMTP Server?
Simple Mail Transfer Protocol, or SMTP, is used to send mass emails for campaigns aimed at generating cold or warm leads. The sending IP address used by SMTP for this is often formatted as smtp.serveraddress.com.

For example, Gmail sends out emails using the smtp.gmail.com address.
If you’re starting, the IP address linked to your domain is often new. Due to the lack of historical data on which ISPs can base their decision to push your emails, it will be less credible.
ISPs take these steps to protect users of the internet from spam and other dangerous activities.
The likelihood is that your emails won’t meet the requirements and will remain in the spam folder.
ISPs consider email volume to be a key factor in determining spam; as a result, sending emails at first at a low volume and then progressively increasing it is helpful.
In this case, you reduce the number of emails you send daily and then gradually increase it. We call it warming up. Building your reputation with ESPs and ISPs is what it entails. It also aids ISPs in monitoring the activity of their recipients.
The goal here is to let your emails land directly in the inbox rather than spam or junk. The email sending acquires authentication and credibility to increase the chance of sending more and more emails.
How Does SMTP Work?
The SMTP protocol allows you to transmit emails from one IP address to another while transferring email validation to the recipient. As a result, SMTP serves as a crucial email gateway for sending and receiving emails.

This is how email sending works:
- SMTP server processes your email
- Chooses the server to send the email
- And relays the message to that server
- ESPs downloads it and place it in the recipient’s mailbox
Whether the SMTP server is similar to a standard server raises the question. Technically speaking, yes, but it only handles data needed for sending and receiving messages.
They have an impact on where the emails land in the mailbox since ISPs push the emails and ESPs download them. Your emails may be placed there after being marked as spam.
Today, email marketing is a popular choice for lead conversion among businesses. Warming up the SMTP mail server makes it easier to send emails to your audience so they can become clients.
How to Find an SMTP Server for Your Site?
You must be aware by this point that an SMTP server is necessary for sending emails from a domain or website. Since direct email transmission requires your SMTP server to verify before sending, a web application will never do so.
Such a server is rarely offered by your ISP, thus you will need to find a third-party SMTP service provider for this. It is simpler than you might think to locate an SMTP server for any website, even yours.
Follow these steps to determine whether or not a domain is connected to an SMTP server to find out:
1. Click on the “Start” menu or “Windows key” and type “Run.”
2. Now, type “cmd” in the search bar, and you will be redirected to the command prompt application
3. Type any of the two commands ping mail.servername.com or ping smtp.servername.com
As soon as you complete this, the window will show you the server name right after the word “pinging.” This method is obvious, but you can also do this:
- Open the command prompt
- Type ‘nslookup’ and press the enter button
- Write ‘set type=MX’ and then hit enter
- Type the domain name of your site and enter
You’ll see a list of hostnames for SMTP in the results. The domain name must always be preceded by a period (.) in the command prompt and every other time while looking for an SMTP server. Make sure your website has MX records as well; otherwise, there won’t be any results.
If you use Linux, adhere to the following instructions to get the SMTP server address:
- Open the command prompt
- Type ‘dig domain. name MX’ and hit enter
The SMTP server for the entered domain name will appear right away. There’s a strong probability that there isn’t an SMTP server configured for your domain if your DNS server returned no results. You can either do it yourself or contact the tech support team of the business that is hosting your website.
Reasons You Must Warm Up an IP Address of Your SMTP Server
Whenever you create a new IP address for the SMTP, it’s crucial to warm it up. Otherwise, most of your early emails are likely to be marked as spam.

Here are a few reasons why you must warm up an IP address:
1. Warming up the IP ensures high delivery or success rate for your emails.
2. With an SMTP server IP warmed, you can send tons of emails.
3. Use extra features that come with SMTP service, allowing you to efficiently measure campaign stats, such as conversions, bounce-offs, subscribes and unsubscribes, and more.
4. Finally, warming up the IP ensures that the said server is recognized as one of your trusted SMTP servers by all mail clients, which minimizes the chances of your emails ending up in spam folders.
Send emails from the IP to your email address or other reputable Gmail or Yahoo Mail accounts to warm up the IP. If you so choose, you can also set up your SMTP server.
How to Warm Up SMTP Server IP
It is simple to warm up the SMTP server IP address, but it does take time and effort. To warm up your SMTP server IP and improve email open rates, follow these simple instructions.
Set Up DKIM and SPF Records
First, configure DKIM and SPF records by your needs. DKIM stands for DomainKeys Identified Mail, a standard that makes sure emails aren’t altered in any manner. In contrast, the SPF identifies the sending servers.
This is how you set up the SPF records:
- Identify mail servers you use to send email from your domain.
- Make a list of your sending domains.
- Create your SPF record.
- Publish it to the DNS.
- Test and confirm everything is in place.
And this is how you set up the DKIM records:
- Generate the domain key for your site.
- Enter the public key into your domain’s DNS records.
- Set up DKIM signing to include the signature to all outgoing emails.
This step sets the basis of your whole build-up strategy, so be careful while creating these records for better email deliverability.
Start Warming Up SMTP Server IP
As soon as the record-setting is complete, begin warming up your SMTP server IP. The process of rolling out emails and scaling them should begin right away.
Start by only emailing your most-trusted fans 10–20 times each day at first. You can progressively boost email sending once interaction rates are high.
Up Your Email Sending Reputation
As an email sender on an SMTP server, you must establish a solid reputation before moving on to the next step. But even though the procedure is simple, it takes time.
ISPs evaluate the reputation according to these factors:
- Bounce rates
- Spam traps
- Content quality
- And recipient’s behavior
So if you want to warm up the SMTP server IP, you must:
- Ensure you’re following the best email sending practices
- Not use any blacklisted words or do the keyword stuffing
- Try A/B testing to monitor the behavior of your audience
- Not send the promotional emails when warming up the SMTP
- Add email signature and other ‘personal’ details
- Stick to fewer than two font styles
- Routinely filter your email senders list
- Keep the CTA above the fold
- Don’t use ‘No-Reply’ in the sender’s email address
That’s all for now. Let’s summarize the whole thing.
How to Check Your Email Sending Reputation
Do you want to check to see if warming up your IP address aids in reputation building? There are a few tools and services that can assist you in doing that.
- Senderscore.org by Return Path scores your email sending reputation. The score ranks from 0 to 100, 100
being the best. It tells you how you’re performing. Typically it’s
recommended that you maintain your sender score of 90 or better. - Senderbase.com tells you how your reputation is across
all the network providers Cisco manages. The reputation score is
grouped into Good, Neutral, and Poor. - Microsoft’s Smart Network Data Services provides information about the traffic originating from your IP address
such as the volume of sent emails, complaint rates, and spam trap
hits. - Search Console gives access to your domain’s data on Google Search Console.
- AOL Postmaster checks your IP reputation and rates it as “bad”, “neutral”, and “good”.
Summary: How to Warm Up SMTP Server
To successfully sell your business or run effective email marketing campaigns, an SMTP server must be warmed up. If everything is done carefully, the process shouldn’t take more than 2–5 weeks.
To warm up your SMTP server, follow the instructions we’ve provided above. This requires that you gradually expand your email list and establish a reputation over time. Got inquiries? I’d appreciate hearing from you in the comments section below.