Questions About Email Deliverability Issues and Using Similar Domains for Campaigns

Kayla C. · 2026-04-30T23:25:02.922Z

Does anyone in here know a lot about email deliverability? I'm working with a client who is sending emails through Instantly and has been told by a few people they never saw their emails, yet their emails to them were marked as 'open.' They also read that using several emails / domains that are very similar to one another but with a small typo or difference is actually a red flag to email providers. Anyone have any thoughts on this?

11 comments

· Sorted by Oldest

Faizan T.
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Dmed you, everyone is facing deliverability issues nowadays and I've a solutions how to deal with it.
Divyaprasad P.
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That might be because bots opening the emails. Bots can be mimecast URL crawling bots. These bots opens the emails clicks the links in if present for any threat or malware scanning. And hence, you might be seeing these open and such emails are never delivered to prospects. Because these bots don't allow to enter in their mailbox. Hence your prospects are saying they never received any email. Check the error codes against such users, there is chance 550 error or other relevant
🙌1
Divyaprasad P.
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@ Kayla C.
Divyaprasad P.
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(edited)·
1.
I would recommend to warmup domain before sending any email.
2.
Don't use main domain for sending any emails as this will impact domain reputation and increase spam rate.
3.
Instead use sub domain of close variant of your domain. Example: outreach.xyzinfo.com if original domain is xyz.com and email of that subdomain
4.
Apart from Warmup, add this new domain in google postmaster tool and get it verified. There also you will get spam rate, delivery error, and all.
5.
Before sending any email from any domain using any outreach platform, setup SKF, Dkim, DMARC.
6.
Verify these.
7.
Also, run inbox placement test for the email which you are sending to prospects. This will help you understand actually where your email will land in mailbox.
Jimmy H.
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Yep what Divyaprasad P. said… Believe instantly still runs 2 weeks free access while you warm up the domain autonomously.
🙌1
Sourabh
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(edited)·
Hi Kayla, we have reviewed 100+ outbound processes. Happy to understand the situation and provide a solution, Use this audit tool: https://panopticanalytics.com/email-deliverability-audit
Mozahid M.
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Opens without replies almost always mean security bots, not humans. The 'never saw it' problem is usually a different issue — either landing in a promotions/spam tab or getting silently filtered before delivery. What does their domain setup look like? SPF, DKIM, DMARC all in order?
🙌1
Horea
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For deliverability hidden pixels (how you get the "email open" signal) are a big no-no if you are cold emailing
🙌1
Tony D.
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https://mxtoolbox.com/ is helpful for understanding your domain's health.
🙌1
Kayla C.
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Thanks everyone, very helpful! I've had a couple of clients with these issues and this isn't really my expertise but they often ask me about it as I'm helping them with their rev ops flow, integrating platforms, etc.
Patrick H.
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If tacking open rate, you risk getting false positives, while decrease deliverability rate. Ask them to send an email via their system to someone they know who can verify if it lands in the inbox or not. This is a good tool as well for checking spam words (no affiliate😅): https://mailmeteor.com/spam-checker Think overall Google and Microsoft has figured out how to crack down on bulk secondary domains via sequencers etc. This is just my gut feeling on the topic.

Faizan T.
·
·
Dmed you, everyone is facing deliverability issues nowadays and I've a solutions how to deal with it.
Divyaprasad P.
·
·
That might be because bots opening the emails. Bots can be mimecast URL crawling bots. These bots opens the emails clicks the links in if present for any threat or malware scanning. And hence, you might be seeing these open and such emails are never delivered to prospects. Because these bots don't allow to enter in their mailbox. Hence your prospects are saying they never received any email. Check the error codes against such users, there is chance 550 error or other relevant
🙌1
Divyaprasad P.
·
·
@ Kayla C.
Divyaprasad P.
·
(edited)·
1.
I would recommend to warmup domain before sending any email.
2.
Don't use main domain for sending any emails as this will impact domain reputation and increase spam rate.
3.
Instead use sub domain of close variant of your domain. Example: outreach.xyzinfo.com if original domain is xyz.com and email of that subdomain
4.
Apart from Warmup, add this new domain in google postmaster tool and get it verified. There also you will get spam rate, delivery error, and all.
5.
Before sending any email from any domain using any outreach platform, setup SKF, Dkim, DMARC.
6.
Verify these.
7.
Also, run inbox placement test for the email which you are sending to prospects. This will help you understand actually where your email will land in mailbox.
Jimmy H.
·
·
Yep what Divyaprasad P. said… Believe instantly still runs 2 weeks free access while you warm up the domain autonomously.
🙌1
Sourabh
·
(edited)·
Hi Kayla, we have reviewed 100+ outbound processes. Happy to understand the situation and provide a solution, Use this audit tool: https://panopticanalytics.com/email-deliverability-audit
Mozahid M.
·
·
Opens without replies almost always mean security bots, not humans. The 'never saw it' problem is usually a different issue — either landing in a promotions/spam tab or getting silently filtered before delivery. What does their domain setup look like? SPF, DKIM, DMARC all in order?
🙌1
Horea
·
·
For deliverability hidden pixels (how you get the "email open" signal) are a big no-no if you are cold emailing
🙌1
Tony D.
·
·
https://mxtoolbox.com/ is helpful for understanding your domain's health.
🙌1
Kayla C.
·
·
Thanks everyone, very helpful! I've had a couple of clients with these issues and this isn't really my expertise but they often ask me about it as I'm helping them with their rev ops flow, integrating platforms, etc.
Patrick H.
·
·
If tacking open rate, you risk getting false positives, while decrease deliverability rate. Ask them to send an email via their system to someone they know who can verify if it lands in the inbox or not. This is a good tool as well for checking spam words (no affiliate😅): https://mailmeteor.com/spam-checker Think overall Google and Microsoft has figured out how to crack down on bulk secondary domains via sequencers etc. This is just my gut feeling on the topic.