Bulk Email Deliverability Issues

Bulk Email Deliverability Issues

Landing the High-Volume Email Inbox 

Email deliverability requires careful planning. You might be an email rock-star or a fresh faced newbie in need of a little guidance. Everyone’s specific situation is different.

You need common sense and a generous amount of technical know-how. And yet, even minute modifications can make a big difference.  Let’s dive into what it takes to avoid the virtual dead letter office a.k.a  a spam filter or the “junk” folder.

Adorable, creepy delivery cartoon.
Poor deliverability ain’t cute.

Understanding and Improving Email Deliverability

First, let’s define our terms. What is email deliverability?

Deliverability specifies how consistently your email campaigns hit subscriber in-boxes. There are several competing factors that contribute to deliverability such as: quality of IPs, sending speed, content type and software/server set-ups.

If you are having email deliverability issues, here are some ideas to help you trouble-shoot. Again –generally speaking– email delivery issues stem from:

-List hygiene
-IP health
-Email sending protocols.



Hard Bounces are emails that bounced back to the sender undelivered by the recipient’s mail server. This happens because the recipient’s email server blocked your message out-right, or because it was invalid. Reasons for an email being deemed invalid include: misspellings, fake addresses or abandoned email accounts.

Hard bounces are sometimes classified as “spam traps” though, it depends on who you ask. Some say spam traps (like honey pots) are email addresses that were created deliberately, just to catch black hat mailers. Others consider anything that will upset an ISP to be a spam trap. Hard bounces do upset ISPs –as well as ESPs. Ya gotta keep those lists fresh and clean!


Stay off them. Oh..the dreaded SBL (spam block list)!

Block lists are also known as blacklists; lists of domains and IPs caught in the act of  spamming. Different organizations, like SpamHaus, provide this blacklisting service to help email server administrators maintain their sanity (and their job) as they attempt to combat the daily tidal wave of unsolicited email. They subscribe to the list and use it to scrub against the onslaught of incoming messages. If you’re on that list, NO INBOX FOR YOU (Soup Nazi style).

Ne’er-do-well, black hat, mailers are what make it so darn challenging for us good guys. If you’re a well-intentioned, but uninformed email marketer, your messages can easily be mistaken as spam. And once you land on one of these lists, it’s nearly impossible to get off.

Seed accounts are an obvious but frequently overlooked method of keeping tabs on which messages are really making it to the in-box. It’s best to register at least 10 seed accounts per ISP (Yahoo, Gmail, AOL, Hotmail etc.).

To find out your blacklist status, you can try Return Path’s free Senderscore service. Alternately there’s also Lashback Unsubscribe and Blacklist Monitor you can check BEFORE you start blasting away.


Are you using spammy/scammy words in your email campaigns? This has got to be one of the quickest ways to upset an ISP. There are certain obvious words, like “FREE!,” “Ci@lis” or “Nigerian Prince,” that trigger content-based spam filters. The same could be said of crazy, big fonts, inventive punctu@t!on!?! and excessive exclamation marks!!! Employing this kind of visual trickery can get you blocked quickly


ISPs are constantly changing their standards. Your email campaigns’ look and feel might be violating their technical specifications. You must stay up-to-date on ISP sending requirements –which are forever changing. Improperly coded templates provoke spam filter wrath.

“We see this a lot with our clients. A few tweaks here or there can make a big difference,” says VoloMP Head of Client Relations, Chris Doyle. “You’d be surprised what a few little technical changes can do for your email deliverability rates.”

It can be as simple as only providing an HTML version of your message. Some ISPs won’t let you in if you don’t also provide a text version of your email. Also,  incorporating a clearly marked link in your messages requesting recipients add your company’s “from” address to their safe senders list or address book can be a big help. Also phishers and spammers tend to use IP addresses in links to images and pages, so don’t do that.


Internet Protocol addresses! We talk about them CONSTANTLY here at VoloMP. Clean IPs are absolutely critical for all email marketers, but bulk email marketers have to pay extra, special attention to IP health.

High volume email marketers have to become IP warm-up ninjas. Prepping your IPs for mass mailing starts with sending mail at a slow drip. ISPs monitor IPs like a hawk. When a new IP is requesting access to their clients’ in-boxes, the ISP is on high alert. Yes, you’ll set up your feedback loops, Sender Policy Framework (SPF) and Domain Keys Identified Mail (DKIM) but, ISPs want proof (in the form of clicks and opens) that your messages are really welcomed by their clients  –otherwise they will release the hounds on your email.

High-volume email marketers can’t just rely on a handful of golden IPs. Large sends require IP bonding, as ISPs control the number of pings a single IP can perform.

Using multiple IPs for a single send is an advanced strategy. Mailing across hundreds of IPs at a time, protects and even strengthens your reputation while also boosting how fast you can deploy a campaign. Each IP acts as an individual mailing credit score. You want your IPs to be clean and strong so that when you send out a million emails (or much more) your messages arrive in the inbox and in a timely manner.

If you don’t already have an IP warm-up strategy, we can help you get with the program.  We’ll familiarize you with the various warm-up methods and show you how to use our advanced IP throttling tools so you can pump-up the volume while maintaining your IPs.


Don’t get them. If you’re getting too many complaints most likely there’s something off with your sign-up and/or un-subscribe process.  Without subscriber consent, your email marketing efforts will go nowhere, fast. And if you’re making it the slightest bit difficult to unsubscribe from your list, you’re creating a big problem for yourself.

Make sure your subscription practices are in tip-top shape. Your best bet is to follow a double opt-in protocol, make sure your feedback loops are set-up properly and your mailing frequency is consistent.  Use the footer to gently remind subscribers where, when and why they signed up to your list. And, even though you hate to see people leave your list, make unsubscribing a piece of cake. Better to let folks go than get blocked.

Your  subscribers need to know what to expect from you in terms of content and email frequency. If they think they’re signing up for a bi-monthly newsletter about fitness tips but instead,  you’re sending them a daily advertisement for skinny pills, there is going to be a problem. Your subscribers might not only un-subscribe but, also hit the “spam” button just to spite you. If this happens more than a few times, you’re headed for trouble with the ISP.

VoloMP taming ISP filters
Let VoloMP help improve email deliverability


OK, here’s the pitch:

VoloMP has been the leading mailing platform for affiliate marketers for 16 glorious years. All this developing and re-developing of complex emailing software, for high-volume mailers, has trained us in the mysterious ways of ISP filtering.

Do you really want to go it alone?

VoloMP offers both the human touch, as we get you up to speed on the software, and we have the technical goods baked right into the software, to give you the best crack at the in-box when mailing on a massive scale. That’s no easy feat when you’re mailing hundreds of thousands to millions of messages a day.

VoloMP can help you:

Set-up your own IPs and hosting
Register Domain Keys and Feedback Loops
Set-up A (tracks opens & clicks) and MX records (for replies/bounces back to server)
Teach how to send over multiple IPs
Personally guide you on how to squeeze the most our email platform
Customize the software to fit your unique mailing requirements
-Volo:AIO will have their IPs managed for them.

You don’t have to feel lost or stuck as you try to –cost-effectively– ramp-up your sending volume.

When you sign-up with VoloMP you’re getting a trusted confidant to help you navigate the wilds of the bulk email landscape. You get, not only a leading edge mailing platform, but also our email deliverablity expertise.

VoloMP comes email ready, right out of the box. But, everybody has slightly different needs when it comes to getting the mail out. So talk to us. Ask us questions. Interesting or otherwise about email deliverablity or the new face of Pluto. We’re here for you.

You’ve already spent so much time and energy getting your lists and software in place. We know it’s imperative that we help you to deliver. And if it doesn’t work out, no worries.

VoloMP offers a 7-day, money back guarantee.

3 Responses

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