10 Cold Email Practices to Achieve 40% Positive Reply Rate

Created On
July 28, 2023
Cold email practices

We launched Smartlead–a cold email tool—in May 2022 and landed our first customer in the following June.

As we marked our first anniversary, we have decided to acknowledge our day-to-day wins.  

Currently, we are sending 7 million emails everyday with an 18% average reply rate. Being one of the top three warm-up pools, Smartlead is empowering 6800 Businesses with a 42x average ROI. 

Amazing, huh?

If you want to know how we do that using cold emails, read this blog post till the end. You will find our secret cold email practices revealed by none other than Vaibhav—Smartlead founder and CEO—himself. 

Dig in to steal the secrets.

10 Secret Cold Email Practices to Achieve 40% Positive Reply Rates

Everybody knows the basic cold email guidelines but are these enough for a successful campaign? I asked Vaibhav—Smartlead founder—and the answer was NO.

Here are some of the email practices that nobody tells you, but you must know. At Smartlead, our customers have seen as high as 40% positive reply rate following the below practices.

#1 Five Mins Minimum Email Time Gap 

Sending bulk emails is always risky. For instance, sending 100 emails from one email address looks spammy. 

Many marketers use multiple email addresses to avoid that, but only a handful of them know about the email time gap. 

“Keep a minimum of 5 mins email time gap between sending emails”~ Vaibhav

If you are sending a large number (volume) of emails from one email address (within the sending limit), you can continue doing so.

However, you must maintain a minimum of 5 mins time gap between sending emails.  

#2 Maintain a DNC Checklist

DNC or the Do Not Contact (DNC) list is something that nobody tells a beginner. 

A DNC list is a list of leads or domains that you shouldn’t send your messages to. They have either unsubscribed or blocked you, or asked you to stop sending emails. 

“Maintain a DNC list for better email sender reputation”~ Vaibhav

In case you aren’t aware, sending messages to leads that unsubscribed or blocked you is violating the CAN-SPAM Act

Cold email automation tools like Smartlead allow users to create a DNC list on the software itself. So that you can exclude specific leads from receiving any further emails from a campaign, even if they are part of an ongoing campaign. 

#3 Run Campaigns with Less than a 2% Bounce Rate  

While response rate, delivery rate, and clickthrough rate are crucial, marketers mustn’t ignore the bounce rate of email campaigns

If you have launched an email campaign and you are seeing more than 2% bounce rate, then the best initiative is to stop. 

Stop the campaign, check what went wrong, and fix it before resuming it. 

#4 Stop Low Performing Campaigns

“Review the lead quality, copy, and email reputation before resuming a low-performing campaign”~ Vaibhav

Cold email automation tools come with an analytics dashboard where you can see the overall performance of email campaigns. 

The dashboard mainly shows

  • Number of sent emails
  • Open rate
  • Click-through rate
  • Reply rate
  • Bounce rate, etc.

The industry standard for the above email marketing metrics is below:

  • Open rate: >20%
  • Click-through rate: 2-5%
  • Reply rate: >10%
  • Bounce rate: <2%

Campaigns that don’t meet the above metrics should be paused immediately. Review the copy, and assess the quality of the lead list and the email reputation before resuming the campaign. 

#5 Remove Low Performing Email Accounts

A cold email campaign includes several email accounts. While some of those might perform well, some might not. 

At Smartlead, we try to filter out the low-performing email accounts after launching a campaign via the analytics dashboard. 

This is a great way to boost deliverability. It has proven to be highly impactful for us. 

#6 Check Common Spam Blacklists for Your Domain 

“Look for your domain on Common Spam Blacklist”~ Vaibhav

Are your campaigns underperforming recently? Have the open rates dropped down to 5%, and the spam rate gone up?

If yes, there’s a chance that your domain is blacklisted (blocklisted). 

ESPs (Email Service Providers) blacklist a domain or an IP address under suspicion of sending out spam emails. Sometimes, it is also because you are failing the SPF or DMARC authentication or there’s a mistake in the copy that alerted the spam filters. 

Regardless of the reason, it’s important to learn why your campaigns are not performing like before and landing in the spam folder. Is your domain blacklisted?

To know that, you can check out free blacklist checker tools like mxtoolbox.

#7 Send 50 Emails/Addresses per day

Popular ESPs—Google, Yahoo, HotMail, and Outlook—provide a daily sending limit of 500 emails per day. 

But, for a successful outreach campaign, the best practice is to set a sending limit of 50 emails per address per day.  

This has been a highly beneficial practice for us at Smartlead. The above sending limit includes the warm-up emails too.   

#8 Gradually Increase Email Sent Volume

If you are using certain mailboxes to send 10 emails per day, don’t increase the volume suddenly. 

Take a week or two to gradually increase the email volume to 50 or 60 emails per day.

A sudden increase in the number of messages sent will alert the spam filters, eventually affecting the sender reputation score. 

#9 Use Spintax To Randomise Email Messages 

“Spintax improves deliverability by increasing randomization of messages”~ Vaibhav

Spintax or Spin Syntax is a bulk emailing hack that creates variations of sentences or words by using multiple words or phrases in the template

You can add similar words such as {Hey} and {Hi}, separated by a vertical line | 

For example:


This tactic will help you generate a more personalized set of cold emails. Sending email messages with a little variation from one another increases the chances of landing in leads’ inboxes. 

#10 Inbox Rotation

“Select multiple mailboxes per campaign to send the load horizontally”~ Vaibhav

Inbox rotation means sending emails from various mailboxes instead of sending from one mailbox only. 

Here, inbox means one mailbox/email address.

So, the inbox rotation practice means rotating the sender’s account or using various sender addresses to send bulk emails. 

This is a great tactic to divide the email volume into small chunks for several mailboxes. This will help to stick to the “50 emails per day per address” limit. 

Final Thoughts!

The internet is full of cold email tips & tricks. These tips & tricks mainly include

  • Write text-based emails
  • Don’t use multiple links
  • Do A/B testing
  • No spam words
  • Personalization, etc.

While I totally agree with the effectiveness of the above emailing hacks, as a marketer, you need MORE.

You need the secret emailing practice from an experienced email marketer who has already brought the results (multiple times).

If you are reading this, get set, GO. 

Use the above game-changing tips from Vaibhav and let us know the results. If you are looking for automation tools, check out Smartlead.


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Author’s Details

Rajnish Das

Rajnish Das is an in-house writer at SmartWriter and SmartLead. She writes product-oriented, data-driven content for B2B SaaS audiences and educates them on marketing and sales topics. Her expertise includes outbound marketing techniques like cold emailing and LinkedIn outreach.


Edited by:

Charu Mitra Dubey


Frequently asked questions

General Questions

What are active leads?

Active leads are the contacts you upload in Smartlead, similar to contacts in HubSpot; if you upload 1000 leads to a campaign, they are considered 1000 active leads. If you upload similar leads to a new campaign, they are not considered a “new active lead” as they already exist in our system.

Do you provide mailboxes, or do I need to connect my own?

We don’t offer mailboxes yet. You need to get your own dedicated list of mailboxes using popular providers like Gmail, Outlook, Zoho, and others that exist in the market. Once you get them, follow our detailed guides to connect them quickly.

Do you offer guides and articles on succeeding with cold emails?

Absolutely, one of our most popular guides can be found right here. It's been used by a large percentage of users to go from zero to cold emailing experts. Covering all topics from email infrastructure to copywriting and lead sourcing.

Is another tool needed for warmups?

No, Smartlead has over 200,000 highly reputed mailboxes connected. The advantage you get along with naturalized AI conversations is access to aged domains you will never find in any warmup tool.

What is the API commonly used for?

It is used popularly by agencies to automate their entire lead generation process as well as to connect Smartlead to external tools to push and pull data from. You can also connect to 1000s of apps using Zapier.

What type of businesses sees the most success with Smartlead?

Anyone that can close deals from demos will succeed with Smartlead. It works for Sales companies, Marketing agencies, SaaS businesses, Recruitment, and offline companies (like construction).

Do you provide me with lead sources?

We do not provide you with leads. You will need to use other data providers. These leads can be automatically added to Smartlead using our API or bulk uploaded via our CSV upload system.

Do you integrate with any CRMs?

We're building native integrations with Hubspot, Salesforce, Close, Pipedrive, and many more. The best part, due to our open API and Webhook infrastructure, you can connect to any CRM in the world without an issue.

How many team members can I add?

You can add an unlimited number of team members, as well as assign them roles and authority access.

Do you have custom plans beyond the Pro plan?

Yes, it's common for many people to move to Custom plans after a few weeks. You can view all the options for up to 10M leads on the subscription page once you sign up for free.

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