A couple of weeks ago, SendGrid’s email experts Carly Brantz and Ken Apple answered your toughest email infrastructure questions. The conversation sparked many more questions, and they were not able to get to all of them during the webinar. Carly and Ken took some time to respond to the questions they didn’t have time to address here.

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

How do you keep Yahoo (and some others) from deferring your emails from a dedicated IP?

There definitely isn’t one easy solution.  Email deliverability is a science with proven techniques to prevent failures and improve your delivered rates.  If you have the information and tools to manage it, then you can achieve higher return on your email marketing investment in the long run.  I would recommend you read our Email Deliverability Guide for more direction on what you can do to improve your deliverability.

If an IP address gets labelled as “spam” by one of the ISPs, is it possible to “recuperate” the reputation on that? Or is it better to switch to a new IP address? Do ISPs also have some sort of score for domain reputation (irrespective of IP addresses)?

Email reputation is based on your IP address. Contrary to popular belief no reputation is just as bad as having a poor reputation. Using a new IP address should be a strategic move to separate mail streams or move from a shared IP to a dedicated one. You can improve your reputation by simply exhibiting good behavior and beefing up on your best practices and then maintaining that over time.

How would you recommend dealing with 3rd party commercial emails? Would you recommend using a separate IP pool for these? This is a requirement for example to be able to get into the ReturnPath certified program, but won’t your IP reputation drop like crazy when you only send 3rd party commercial emails over an IP?

The reason that SendGrid and others advise against mailing to third party lists is all centered on permission.  A third party list means just that, your company did not get permission, a “third party” obtained the email addresses.  Yes, your email reputation will drop, by keeping a separate pool, which ensures that your legitimate email streams will not be affected by the drop which will be difficult to recover from.

What free tools would your recommend using for not-yet SendGrid users to monitor deliverability?

I would recommend using Return Path’s Sender Score service at www.senderscore.org to get instant, free information on your email reputation and deliverability.

During the IP “warm up” phase, I guess it’s assumed that a lot of emails would land in SPAM instead of inbox since the IP has no/poor reputation. So does getting a lot of your emails land in SPAM work against your IP reputation? How to workaround that problem?

During the warm up phase, if done correctly, you should not set off warning signs to ISPs to block your email.  If you make the warmup process a priority and take a conservative approach over the first month, you should not have many of your emails land in spam.  The warm up process itself is the workaround to being blocked.

What is the rule for using the same IP address/white label for sending both transactional emails and bulk emails?

Ideally, you would keep the different streams of email separate. Remember Ghostbusters – don’t cross the streams!  Then, you can ensure that the higher deliverability that comes with transactional messages that are both anticipated and wanted, won’t be put in danger.  If that isn’t a possibility, I would encourage you to try and combine marketing messages within your transactional emails.  Ask for referrals, include follow and like buttons or offer a promotion at the end of your messages to include a call to action within the transactional message itself.

We are sending double-opt in confirmation messages on a separate IP address. Once a month we resend a confirmation message to users who are not very active.  Occasionally this will trip a “spam trap”; is this going to put us in jeopardy of delivering confirmation messages in the future?

I would advise against mailing to “non-active” users all together.  In fact, a good way to get them off of your list entirely is to do a reactivation campaign to ensure that everyone on your list wants to receive your emails.  Sending to even one spam trap will instantly set back your reputation and cause deliverability problems.  When you send to a spam trap (an email address activated by an ISP to catch spammers), it means you’re engaging in email address harvesting (an illegal practice) or your list hygiene practices are poor.  Either way, ISPs aren’t going to deliver your email.

What is the best way to send Email for maximum deliverbility, Text, HTML or both?

I would always recommend having both.  Including a text version if you are sending HTML emails is a good practice for avoiding a spam filter and it also covers you in the case where the recipient cannot view HTML emails.

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.