General questions

How do I close my Account?

Just send us an email by following address and our support team will help.

Does the amount of email I send from my IP affect my deliverability?

Yes. Generally speaking, you don’t want too few IPs, in case you experience more volume than you expect and you don’t want so many IPs that you look suspicious or spread out your volume over too many IPs. There has to be a balance of volume to IP/domain. Sending too much volume from an IP, sending from too many IPs or sending too little from a range of IPs can all lead to deliverability issues.

Rate limiting allows ESPs proper time to process and filter spam and ensure that transactional email doesn’t get backed up. Without rate limiting in place, ESPs would be even more overwhelmed than they already are. The ESPs all have different sending limits on a per hour, per day basis. Once you hit thresholds with the rate limits, send too much spam, or have any number of other issues, the ISP may start returning error messages. Some ESPs will want you to slow down the sending, stop sending for a period of time, or change your habits (due to bad engagement, bad reputation, etc). We automatically adjust your sending rates according to the feedback from these ESPs to keep you in their good graces. Generally, these rate limits are on a per IP address basis. Contact our Support Team if you wish to purchase additional dedicated IP addresses for your account.

Account Reputation

Every SmartSender account has a reputation and quota. These two features help to protect us from spammers that would otherwise send a lot of emails quickly, that could then damage the reputation of our sending servers and negatively affect other SmartSender users.

An account’s reputation can be Bad, Low, Normal, Good. SmartSender uses many heuristics to define an account’s reputation. We look at how many bounces, spam complaints, unsubscribes, and failed content reviews the account has to set the reputation value.

I want to learn more about Deliverability and Email?

One of the best resources is the blog Word to the Wise. Also, Return Path is a service that enhances deliverability and they publish a lot of great information through their blog and white papers. Below are are some best practices from the major ESPs.

What is the difference between hard and soft bounces?

You can think of hard bounces like permanent errors and soft bounces as temporary errors.

We will stop attempting delivery after one hard bounce. With soft bounces, we keep trying to deliver but eventually we will stop trying to deliver in accordance with the receiving ESP’s feedback.

Can I use SmartSender to track what happens with my emails?

SmartSender tracks all of the typical events that occur with emails: Opens, Link Clicks, Bounces, Unsubscribes, Spam Complaints and everything you can ever need. We make that data available to you via the Dashboard or through the API.

Why not just use Sendmail + Postfix + Courier IMAP?

You can but you should be aware that there is a permanent war between Email Service Providers (ESP) and army of spammers. ESPs were forced to place numerous technical barriers to be able to stop spammers. Even though you are sending authorized emails you would have to take into account all that barriers to deliver to inbox and avoid junk folder.

You need to setup and authenticate an appropriate infrastructure

Register your IP addresses and monitor their reputation

Build and manage complicated ensemble of software, hardware and dedicated people team.

Can I send to more than one recipient at a time?

No. At this moment you can send to only to one recipient at a time. We have this limitation to be able to provide you with detailed statistics on each email sent.

Can I send customized messages with SmartSender?

With SmartSender you can create highly customized messages. It’s possible to put any information that you gather with your system into email (registration date, purchase date, client’s name, purchased product or whatever you need). Through SmartSender’s API you can send emails with needed content to any of your customer in desired time with only one simple request.

What types of email can I send with SmartSender?

SmartSender is an email infrastructure service designed to help applications or websites that need to send transactional email like password resets, order confirmations, and welcome messages, autoresponders, marketing campaigns and regular notifications. View our Terms of Use for additional details.

Note: You must add SPF and DKIM records and verify ownership of your sending domains before you can send email through your account. SmartSender will not send any email from unverified domains or domains without valid SPF and DKIM records, including public domains like,, and more. Mail sent from unverified domains or domains without valid SPF and DKIM records will be rejected at the time of sending, with the rejection reason, unsigned. Learn more about SPF and DKIM and domain verification, or manage sending domains in your SmartSender account.