SendGrid’s email experts Carly Brantz and Paul Kincaid-Smith hosted a webinar last week offering tips on how to improve your sender reputation. We received so many great questions that we weren’t able to get to them all. Carly and Paul wanted to continue the conversation on the SendGrid blog and address some questions they didn’t have time to answer last week.

If you missed the webinar, you can access a recording here.

How do outlook users complain that a message is spam?
PKS: They complain through the junk email reporting tool plugin that works to improve the Microsoft Outlook spam filter. They may also use a third party Outlook plugin like Cloudmark to report spam

What is an ESP?
CB: An ESP is an email service provider. They are organizations that provide email servers to send, receive and store email for organizations and/or end users. They can also be a company which offers email marketing or bulk email services.

I am having a very bad problem with my emails. I have a membership site and my sign-up confirmation emails are being blocked because my IP is on several blacklists. If I get a dedicated IP will this solve the problem?
PKS: Yes, your transactional emails (like sign-up confirmations) are more likely to be delivered if you send them from a dedicated IP. If you also plan to send marketing emails (which are more likely to be reported as spam), we suggest you send those from a sub-account with a separate dedicated IP address.

RE: Hard bounces… what would be the best practice to permanent errors that are the result of anti-spam filters rejecting emails to a certain address? Should I remove the address entirely, or try again later after identifying the problem?
PKS: If a spam filter issues 5xx permanent errors, you may wish to move that recipient’s address from your list and add it to a separate list to try again (cautiously, in small amounts) at a later date once your sending reputation improves.

SPF can be tricky to get right, especially with other senders. Your thoughts on using and sending SPF?
CB: I’d say it is considered best practice to implement SPF along with SenderID and DKIM, especially if you are a high volume sender. In the absence of authentication of all your emails, it is very difficult for an ISP to confirm that you are in fact a legitimate sender. Learn how to authenticate your email in 5 easy steps here.

Is there a big/market leading spam filter that all the email servers work with, like Google is for search for instance?
PKS: There is no one single spam filter used by all receiving mail servers. Many solutions incorporate a multi-layered approach with filter technology from multiple sources. Filter popularity varies by geographic region and by receiver type. Small businesses will use a different type of protection than a large ISP, for example. In North America, many ISPs use Cloudmark Authority as part of their multi-layered inbound filtering solution. Other popular filters include SpamAssassin, Ironport, among many others. Most large receivers also use RBLs (realtime block lists) like Spamhaus’s SBL as a first line of defense. Many large webmail providers also layer on their own homegrown filtering logic.

Should I permanently remove “quota exceeded” email addresses from legitimate recipients?
CB: I think a good rule of thumb is to remove an email address that has soft bounced three times without any trackable activity.

I have a CRM web app that has many users with very limited email capability through SendGrid. I am thinking of having a “mass email” function to allow my users to send emails to their contacts list. How can I avoid one user ruining it for everyone else? Emails will be “from” each user’s email addresses – does that help? Or do the powers that be only look at the originating IP address?
PKS: Currently, many receivers will block by IP, so if one of your users sends a large spam run, other users sharing that IP are at risk of being blocked. You could minimize the risk of this collateral damage several ways:
1) Check all outbound mail with a spam filter, like SpamAssassin before you submit it to SendGrid.
2) Split your users across multiple IPs (your SendGrid account can utilize multiple dedicated IPs). New, untrusted users could be assigned to a different IP than trusted users with a good sending history.
3) If each of your users is a distinct SendGrid sub-account, you can track their complaints, open rates, click rates, etc. to identify the troublemakers. SendGrid’s event API will help you monitor the health of these sub-accounts in real time. Bottom line, you need to plan for trouble and have the people, policies (terms of service), processes and tools in place to prevent and identify bad behavior.

How does DMARC fit into this, or into SendGrid’s solution?
CB: Great question! We have an entire blog post addressing this issue here.

Are blacklists shared/centralized among MTA’s, or are they always separate ones maintained by each MTA?
PKS: Many big receivers subscribe to shared third party blacklists (like Spamhaus SBL, or SURBL), and some also maintain their own local blacklist.

How do domains affect spam, it seems like a lot of spam now (e.g. SEO) is sent from gmail versus a corporate domain.
PKS: You’re right, spammers try to bypass spam filters by using domains that have a good sending reputation. As you point out, some spammers try to piggy-back on Gmail’s sending reputation. They can be caught if they spoof (forge) the From address to be (Some receivers check’s SPF record to detect that the spoofed mail is not coming from an authorized IP address. Gmail’s outbound spam detection team works hard to identify and lock real Gmail accounts that send spam.)

Would you use SendGrid to replace a sending MTA and/or regular double opt-in corporate newsletters?
CB: Both. SendGrid helps you focus on your business without the cost and complexity of owing and maintaining an email infrastructure. Our technology, advanced analytics, and flexible APIs are designed for all types of email – from transactional messages generated by an application to double opt-in marketing campaigns.

Does it harm my reputation if I change the “From” name when using the same email address (even if it is beneficial to my customers)?
PKS: Email addresses can be divided into two parts, the “Friendly From” and the routable part. For example, “Franklin Fasteners” <>. We don’t think you’ll incur a reputation hit if you change the “Friendly From” part (e.g. “Franklin Fasteners”) but you are more likely to incur a reputation hit if you change the routable part. Not all system use the “from” address for reputation, but some do. They are more likely to associate your sending reputation to your IP or your DKIM signature (inserted into your message headers) or a combination of both.

Can I send through the same email from a different domain name on a daily basis?
PKS: You can send the same message content from a different domain on a daily basis, but many spam filters will recognize similar content from different domains, so if one domain gets a bad reputation, messages with the same format or content will probably be blocked too.

We have been on board with SG for a few weeks and we are constantly improving our practices, but for some reason our reputation has not improved.
PKS: Your sender reputation is affected by the number of spam complaints. If you got off to a bad start and sent to a lot of recipients who didn’t want your message, some of them may have marked the message as spam. Sometimes people will mark messages as spam days or weeks (even months!) after receiving the message. If a steady (but hopefully declining) stream of spam complaints trickles in, then that will degrade your sending reputation. The reputation is bound to improve after the complaints abate. Also ensure your bounce rates are low. Have you checked to see if your sending IP or domain is on a blacklist? (Try with both.) If you are blacklisted, sometimes you’ll be able to discover the reason and reach out to get yourself delisted once you’ve made the necessary changes to your sending practices.

My list is past customers and people that signed up for email specials and promotions. Some of the names are 10 years old. How does SendGrid help in cleaning that up? What do I do and what does SendGrid do?
CB: SendGrid delivers the mail you send. You are responsible for your own list hygiene. That being said, a win-back campaign could be a great way to clean up your list and identify engaged users. Take your list and ask them to “subscribe” to your list and outline exactly what they would receive. This is a great way to take advantage of the names you already have but to ensure they are active and interested.

As SendGrid's Senior Marketing Analyst, Danny is responsible for keeping the marketing team focused on making data-driven decisions to help make sure we are providing value for our customers and prospects. While he may spend his days knee deep in spreadsheets now, Danny spent most of the last 10 years managing email campaigns, website optimization, and PPC campaigns for B2B companies.