4 Things You Need To Know About Message Queue Management

Bird

7 Jul 2014

Email

1 min read

4 Things You Need To Know About Message Queue Management

Key Takeaways

    1. Monolithic queues quietly break your email program
      Many senders run on MTAs that use a single, shared queue. When anything slows or breaks (like one bad campaign or a tarpit), everything in that queue suffers—often causing delays you mistake for “normal email problems.”

    2. Shared queues turn one bad stream into everyone’s problem
      If one traffic stream gets tarpitted (e.g., Yahoo throttling a problematic campaign), messages behind it in the same queue also back up—impacting transactional emails, other brands, or other campaigns that are totally innocent.

    3. Queue issues eventually become reputation issues
      If tarpitting and blocking aren’t isolated and fixed, they drag down the IP’s reputation. Over time this can lead to blocklisting, higher bounce rates, and spiraling infrastructure costs as you try to “fix it with more hardware.”

    4. Momentum isolates traffic by domain and stream
      Momentum creates separate receiving-domain queues per traffic stream (e.g., Yahoo for transactional vs Yahoo for bulk). If one stream hits issues, it doesn’t slow the others. Problems are contained, easily diagnosed, and fixed without stopping the world.

    5. Per-domain visibility makes remediation fast
      Because Momentum manages delivery and diagnostics down to the receiving domain and IP, you can quickly see which streams are bouncing, why, and where tarpitting or blocking is happening—so deliverability and ops teams can act immediately.

Q&A Highlights

  • What is message queue management in email?

    It’s how your MTA organizes and processes outbound messages—deciding which messages go out, in what order, and how they’re retried when a receiving domain slows or rejects traffic.

  • What’s a monolithic email queue?

    A monolithic queue is a single, shared queue that holds all outgoing mail together—regardless of sender, campaign, or recipient domain.

  • Why are shared or monolithic queues a problem?

    Because if one sender or campaign runs into trouble (like throttling or blocking), it can delay everything else sitting in the same queue, including critical transactional mail.

  • What is tarpitting in email delivery?

    Tarpitting is when a receiving domain deliberately slows down SMTP responses to a sender it finds suspicious—stretching out responses to the maximum allowed time and effectively throttling that sender.

  • How does tarpitting affect delivery?

    Tarpitted messages move very slowly through the queue, causing backups behind them. In shared queues, that means unrelated messages are delayed too.

  • How do queue problems impact sender reputation?

    If tarpitting and blocking aren’t isolated and addressed, they lead to high bounce rates, repeated retries, and poor engagement—hurting the reputation of the IPs and domains involved.

  • How is Momentum’s queue architecture different?

    Momentum creates per-domain queues per traffic stream, and processes them in parallel. A problem with one domain or stream doesn’t stall other domains or mail types.

  • What’s an example of how Momentum isolates issues?

    If a 50,000-message bulk send is throttled by Yahoo on one stream, it won’t delay Yahoo traffic for other streams—like password resets or other customers’ mail.

  • How does Momentum help diagnose queuing issues?

    It provides per-domain, per-stream statistics (like bounce types and rates), so operators and deliverability teams can see exactly which traffic is in trouble and why.

  • Why doesn’t “just adding more hardware” fix queuing problems?

    If the queuing model is wrong (shared queues, poor isolation), more servers just replicate the same bottlenecks and complexity—raising costs without fixing root causes.

  • What kinds of email are most sensitive to queue problems?

    Transactional and time-sensitive emails (password resets, alerts, receipts) are hit hardest by delays caused by bulk campaigns sharing the same queues.

  • How does better queue management improve ROI?

    By isolating and resolving issues quickly, you keep critical mail fast, protect IP reputation, reduce support noise, and avoid over-investing in hardware just to fight symptoms.

#1 Poor Message Queuing Capabilities are the Root Cause of Many Sending Problems

Many senders have no idea that the poor queuing capabilities of their email infrastructure are the root cause of their sending problems. Open source solutions use a very rudimentary approach of utilizing a single monolithic queue to manage traffic which creates many email deliverability issues. Many senders have dealt with these issues for so long that they accept it is just part of the business of sending email.

Many senders have no idea that the poor queuing capabilities of their email infrastructure are the root cause of their sending problems. Open source solutions use a very rudimentary approach of utilizing a single monolithic queue to manage traffic which creates many email deliverability issues. Many senders have dealt with these issues for so long that they accept it is just part of the business of sending email.

Many senders have no idea that the poor queuing capabilities of their email infrastructure are the root cause of their sending problems. Open source solutions use a very rudimentary approach of utilizing a single monolithic queue to manage traffic which creates many email deliverability issues. Many senders have dealt with these issues for so long that they accept it is just part of the business of sending email.

#2 Shared Message Queues Cause Delays

Most commercial MTA server products are little better. They force traffic into a limited number of shared queues, creating major stability problems when any one of the traffic streams encounters problems. When receiving domains deem certain content or sending practices suspect, they “tarpit” traffic from the offending sender. Tarpitting slows the acceptance of a message to a crawl by drawing out server responses to the maximum time allowed (as specified in the Simple Mail Transfer Protocol). Tarpitting causes messages queued behind the offending message to back up, delaying everything else in the shared queue. Clearing or sidelining the affected traffic could alleviate the problem. But with queuing architecture of this kind, even just determining which messages in a shared queue are causing the problem can be very time consuming.

When using a shared queue and one sender’s large mailing is submitted, these messages are placed at the front of the queues. When a subsequent mailing or transactional message is submitted, those messages are then placed in the queue behind the first mailing. Typically, this queue contention will cause the sender of the second mailing to experience delays, which will often prompt complaints and calls to the IT support operations.

Most commercial MTA server products are little better. They force traffic into a limited number of shared queues, creating major stability problems when any one of the traffic streams encounters problems. When receiving domains deem certain content or sending practices suspect, they “tarpit” traffic from the offending sender. Tarpitting slows the acceptance of a message to a crawl by drawing out server responses to the maximum time allowed (as specified in the Simple Mail Transfer Protocol). Tarpitting causes messages queued behind the offending message to back up, delaying everything else in the shared queue. Clearing or sidelining the affected traffic could alleviate the problem. But with queuing architecture of this kind, even just determining which messages in a shared queue are causing the problem can be very time consuming.

When using a shared queue and one sender’s large mailing is submitted, these messages are placed at the front of the queues. When a subsequent mailing or transactional message is submitted, those messages are then placed in the queue behind the first mailing. Typically, this queue contention will cause the sender of the second mailing to experience delays, which will often prompt complaints and calls to the IT support operations.

Most commercial MTA server products are little better. They force traffic into a limited number of shared queues, creating major stability problems when any one of the traffic streams encounters problems. When receiving domains deem certain content or sending practices suspect, they “tarpit” traffic from the offending sender. Tarpitting slows the acceptance of a message to a crawl by drawing out server responses to the maximum time allowed (as specified in the Simple Mail Transfer Protocol). Tarpitting causes messages queued behind the offending message to back up, delaying everything else in the shared queue. Clearing or sidelining the affected traffic could alleviate the problem. But with queuing architecture of this kind, even just determining which messages in a shared queue are causing the problem can be very time consuming.

When using a shared queue and one sender’s large mailing is submitted, these messages are placed at the front of the queues. When a subsequent mailing or transactional message is submitted, those messages are then placed in the queue behind the first mailing. Typically, this queue contention will cause the sender of the second mailing to experience delays, which will often prompt complaints and calls to the IT support operations.

#3 Message Queuing Issues Affects Sender Reputation

Left unaddressed, tarpitting and blocking issues will degrade the reputation of the associated IP addresses, and senders can find themselves in the unfortunate position of getting placed on ISP blacklists. Juggling senders and adding hardware can address the problem, but the process is manually intensive, costly and introduces operational risk. Without an effective solution, many companies find the profitability of their email operations eroding as costs outpace the growth of their revenue streams.

Left unaddressed, tarpitting and blocking issues will degrade the reputation of the associated IP addresses, and senders can find themselves in the unfortunate position of getting placed on ISP blacklists. Juggling senders and adding hardware can address the problem, but the process is manually intensive, costly and introduces operational risk. Without an effective solution, many companies find the profitability of their email operations eroding as costs outpace the growth of their revenue streams.

Left unaddressed, tarpitting and blocking issues will degrade the reputation of the associated IP addresses, and senders can find themselves in the unfortunate position of getting placed on ISP blacklists. Juggling senders and adding hardware can address the problem, but the process is manually intensive, costly and introduces operational risk. Without an effective solution, many companies find the profitability of their email operations eroding as costs outpace the growth of their revenue streams.

#4 Momentum’s Intelligent Message Queuing Capabilities Resolves Tarpitting & Blocking Issues

A key differentiator between Momentum and other commercial or open source solutions is this: as traffic is processed, Momentum creates a set of receiving domain queues for each traffic stream.

Flowchart showing content generator pathways for different customers, detailing their traffic segments, independent queues, and destination domains such as Yahoo, Gmail, Outlook, and AOL.

Each queue is then independently processed in parallel with the others. For example, a mailing with 50,000 messages that is throttled by the Yahoo queue for one traffic stream will never cause delays to Yahoo queues of other traffic streams. Transactional or bulk traffic will have no impact on any of the other traffic streams, and any tarpitting or blocking problem is limited to a tiny, easily detected fraction of the overall traffic.

Because Momentum enables management down to the receiving domain of each sending IP address, it can easily provide diagnostic statistics at the same level of granularity. The operator can see which traffic streams have unusually high bounce rates and what types of bounces are occurring most frequently, thereby providing the operator and the deliverability manager the information required to immediately begin remediating the issue.

Learn more about why monolithic and shared queues used by commodity MTAs are detrimental to the speed and effectiveness of delivering messages in the Momentum vs Commodity MTAs white paper.

A key differentiator between Momentum and other commercial or open source solutions is this: as traffic is processed, Momentum creates a set of receiving domain queues for each traffic stream.

Flowchart showing content generator pathways for different customers, detailing their traffic segments, independent queues, and destination domains such as Yahoo, Gmail, Outlook, and AOL.

Each queue is then independently processed in parallel with the others. For example, a mailing with 50,000 messages that is throttled by the Yahoo queue for one traffic stream will never cause delays to Yahoo queues of other traffic streams. Transactional or bulk traffic will have no impact on any of the other traffic streams, and any tarpitting or blocking problem is limited to a tiny, easily detected fraction of the overall traffic.

Because Momentum enables management down to the receiving domain of each sending IP address, it can easily provide diagnostic statistics at the same level of granularity. The operator can see which traffic streams have unusually high bounce rates and what types of bounces are occurring most frequently, thereby providing the operator and the deliverability manager the information required to immediately begin remediating the issue.

Learn more about why monolithic and shared queues used by commodity MTAs are detrimental to the speed and effectiveness of delivering messages in the Momentum vs Commodity MTAs white paper.

A key differentiator between Momentum and other commercial or open source solutions is this: as traffic is processed, Momentum creates a set of receiving domain queues for each traffic stream.

Flowchart showing content generator pathways for different customers, detailing their traffic segments, independent queues, and destination domains such as Yahoo, Gmail, Outlook, and AOL.

Each queue is then independently processed in parallel with the others. For example, a mailing with 50,000 messages that is throttled by the Yahoo queue for one traffic stream will never cause delays to Yahoo queues of other traffic streams. Transactional or bulk traffic will have no impact on any of the other traffic streams, and any tarpitting or blocking problem is limited to a tiny, easily detected fraction of the overall traffic.

Because Momentum enables management down to the receiving domain of each sending IP address, it can easily provide diagnostic statistics at the same level of granularity. The operator can see which traffic streams have unusually high bounce rates and what types of bounces are occurring most frequently, thereby providing the operator and the deliverability manager the information required to immediately begin remediating the issue.

Learn more about why monolithic and shared queues used by commodity MTAs are detrimental to the speed and effectiveness of delivering messages in the Momentum vs Commodity MTAs white paper.

For more information about Message Queue Management, download A Deep Dive into Momentum’s Intelligent Queuing Architecture.

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