Deliverability FAQ

The email sizes and the warning thresholds are specified in the following table:

The data is loaded into the Deliverability Report database every 4 hours. However, since deliverability data depends highly on the actual behavior of the contacts, it may make more sense to check the results 12-24 hours after campaign launch. By that time the data should stabilize and will not be prone to change drastically.

Domain-level opens and clicks are calculated from the Emarsys database, using our contact behavior data. This data is usually kept for 13 months.

The seedlist data, however, is always queried real-time from our partner, Return Path. This also means that after 30 days it is no longer available on Return Path’s side.

However, we have a service that preserves this data for 13 months as well. This data is displayed in the Inbox Monitor section of the Deliverability report.

The report database only calculates the results for the Top 10 domains for each launch. If you want to get more granular results you need to split your recipient list with this in mind. This can be done with A/B versions or child campaigns, too.

A seedlist is a list of email addresses at different ISPs, maintained by Return Path. By sending the campaign to these addresses, we can estimate the inbox placement of the emails at different ISPs. The number of seed addresses changes dynamically and the list is monitored and updated by Return Path. We at Emarsys always use the most up-to-date version.

We use a seedlist when the recipient count of the campaign is at least 10,000. The seedlist data is available in the Inbox Monitoring section of the Deliverability Report.

If Deliverability Report indicates a problem, but there is no seedlist data available, that means that Return Path does not have a seedlist for that particular ISP.

No, you cannot use the seedlist yourself and you cannot add new addresses to it. If you would like to have more functionality, you can sign up for a Return Path account, or you can have your own seedlist, that you can upload and monitor in a separate segment.

IP reputation is the ISPs first impression of you, when they determine the Spam Score of your email. This shows the state at the moment of sending and it is one of the most objective metrics to show your general reputation. The following table shows the reputation values and their most likely consequences:

ISPs want to filter out spam for your contacts. Spam mail is not only unwanted, but can also contain phishing links, and other malicious things. To this end, they have a scoring system, called Spam Scoring.

The Spam Score is ever changing, and the metric is not public, but when you are sending, ISPs assess every mail based on the sender domain.

First, they check the authentication of the email. If it is OK, they check image and link domains, looking for phishing links. They also check the content against best practices; our Deliverability Advisor is helpful in this field: e.g. is there a text version, are you sending consistent volumes?

If you think that your Spam Scoring may be high, you can use IP warm-up to handle this.

When you start to use a new IP address, you have to introduce yourself to the ISP. This is called IP warm-up.

Take your whole contact list and segment to your absolutely most engaged contacts, the ones that will most certainly open and click, and start sending good content to these contacts. During the warm-up process, you build your reputation in about four weeks, with consistent volume and consistent content. You can slowly increase the number of contacts you are sending, until you reach the desired size of the segment.

If you miss this, the ISP will only see the highly inconsistent increase in volume and they will most likely handle you accordingly (e.g. block).

IP warm-up can also be used to tackle deliverability problems.

You can use the same reply address, but since this can affect your deliverability, as best practice, we strongly recommend separating your marketing and transactional sender addresses, based on the actual use case.

Yes, but an IP with a low reputation can seriously affect your deliverability. As best practice, separate your marketing and transactional emails. In general, transactional messages have better engagement and thus better deliverability, and if you do not separate marketing from this, your potential marketing problems will affect the inbox placement of your transactional mails, too.

However, maintaining a good deliverability is not rocket science, you just need to be mindful about your strategy and apply best practices.

You can check your reputation at Senderscore.org or in the Deliverability Advisor, if you have a dedicated IP address. 

No, unfortunately, this is not possible. However, your account's blacklist can be updated via the API. For more information, see Blacklist Emails and Domains.

Yes, but please note that no imports are processed between 6-11 AM GMT+1 (Vienna time). This practically means that in the worst case, an update at 6 AM may take 5 hours to process.

By using the API, your account's blacklist is updated in real time.