Deliverability FAQ

Get your burning email deliverability questions answered!

Updated over a week ago

Email marketers know the importance of deliverability for a successful email program; from authentication to sending the right content at the right frequency to your engaged customer base. Deliverability is all about making sure that your audience is getting relevant messages.


Q: What exactly is email deliverability?

  • A: Deliverability is the ability to deliver emails to the inbox, or rather the Inbox Placement rate of your email campaigns. Emails can land into any tab – Primary, Promotion, or Update based on the type of message. Some marketers confuse the term “delivered rate” with deliverability, which leads them to have a false perception of their deliverability. The delivered rate gauges the number of emails that weren’t bounced. It doesn’t give you any insights on which folder your emails were delivered to —inbox or spam folder.

Q: What are DNS records and why do we need to configure DNS?

  • A: DNS (domain name records) are used to link the domain names to the assigned IP addresses and vice-versa. These authorize the sender to send emails on your behalf. With updated DNS, a system is capable enough to deliver the emails to your recipient's inbox without it being marked as Spam / Blocked.

Q: How is DNS setup completed?

  • A: DNS setup takes place on your end. Bluecore’s Deliverability team generates DNS records on the SendGrid platform and shares those records with you. Your IT team can update them on your DNS management tool. After you update them, we validate those records back on SendGrid.

  • Below are the authentications to be configured in DNS Setup:

    • MX Records

    • SPF Record (Sender Policy Framework)

    • DKIM Record (DomainKeys Identified Mail)

    • PTR Record (Pointer Record)

    • Google Authentication key

Q: Why do we need separate subdomains for transactional and promotional emails?

  • A: The sending domain is a key identifier for Internet Service Providers (ISPs). As such, ISPs will treat them separately to a certain extent and associate a reputation with each of the subdomains.

  • The reason you would want to separate transactional and promotional is to differentiate the two mail types and avoid getting a negative impact from the marketing subdomain to the transactional subdomain. Promotional campaigns involve more risks (list acquisition, frequency, content, etc), while transactional messages are time-sensitive & critical in nature. Isolating the two is particularly important for the protection of the transactional messages.

Q: What is the exact timeline of a warm up?

  • A: The average time frame is 4-6 weeks. However, the warm up timeline is going to be specific to your business and will be dependent on other variables like sending consistency (we recommend a minimum of 3-4 sends in a week), percentage of active users in your database (180 days vs older audience), the average unique open rate of your existing promotional campaigns, inbox placement across different mailbox providers.

  • Your dedicated deliverability manager will customize a plan based on your business needs & sales cycle.

Q: Can you explain the warm-up process at Bluecore?

  • A: We start with a new subdomain of your choice & work on building a sender reputation for your new subdomain & IPs. Mailbox providers throw a lot of caution when receiving emails from a new domain, so our deliverability advice will center around sending to your most engaged users in the first few weeks.

    • A 4-6 week schedule is the minimum for warm-up. Based on your list size, we might need to warm up for 6 to 8 weeks.

    • It is important to mail to the most recent & active subscriber list during the warm up period.

    • Adjust the warm up plan based on bounce / spam metrics.

Q: Why do we need a minimum number of sends & a set cadence to warm up to peak volume?

  • A: Mailbox providers like Gmail & Microsoft work on smart algorithms. Your domain & IP reputation gets a reputation based on a number of factors. One of the factors is the sending pattern of your new IPs over the first few weeks. If the IPs traffic levels drop below "big enough to notice" volume for any major mailbox providers, then the deliverability team will need to start from scratch when you start mailing again. For example, if your weekly sends are scheduled randomly or with an irregular pattern, then the IPs will get a negative sender reputation score from Gmail & Microsoft.

  • Your deliverability manager will work with you to set up a consistent sending pattern during the warm up phase.

Q: Can you do a fast warm up to achieve our peak volume?

  • A: IPs can send millions of volumes in a day and as your ESP, we have the capacity to send higher volumes using shared infrastructure. But in order to build a great sender reputation, we will do both reputation-building & IP-warming simultaneously.

  • Inbox providers ultimately control how aggressive you can be as a sender. The consequences can be bulk spam folder placement for all your marketing emails from your subdomain. Senders need to gradually increase their sending volume and build a consistent sending pattern during a warm up phase.

Q: What is the engagement data I will need to provide to Bluecore? What to do if my ESP is not helping to export the data?

  • A: You will need to provide the email list with the tag “last open date”. If there are any users who never opened an email, you may simply provide those audiences without any tag. These audiences must be opted-in users.

  • Unfortunately, if your ESP doesn’t support exporting lists with open dates, please provide separate lists for the last 7-day openers, the last 15-day openers up to the last 365-day openers. If this is also not possible, you may provide openers in whatever way your ESP supports.

Q. How many email creatives are required during the warm up process?

  • A: The number of unique email creatives will depend on how frequently you are touching a set of the same audiences during warm up. A minimum of 5-6 email creatives are required to ensure your audiences are not getting the same content every time which could result in low engagement.

Q: What should I do when a specific ISP is blocking my emails?

  • A: There are several reasons for an ISP’s blocking your emails. Your domain or IPs might be blacklisted by the ISP. There is an automated delisting process for most of the blacklisted providers, but manual intervention is needed for ISP blocks. The delisting will be done based on the bounce reason we receive in the bounce logs. Bluecore’s deliverability team actively checks for any major block listings and helps with the mitigation.

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