Get out of spam. Stay out of spam.

Most professional email deliverability audits in 2026 cost between $500 and $5,000 depending on sending history, the number of ESPs, campaign scale and infrastructure. Full details are on the audit page - we scope it on the discovery call and give you a fixed quote before any work begins.

One-off problem and you want the full picture: audit. A specific question you need answered by a specialist: consultation. You never want to think about deliverability again: a monthly retainer package.

Yes - we are ESP-neutral and have worked across all major platforms (Google Workspace, Klaviyo, SendGrid, Amazon SES, Mailchimp and more) as well as self-hosted stacks.

It depends on the cause. Configuration issues - missing or misaligned SPF, DKIM or DMARC, bad reverse DNS, a blacklist listing - are often diagnosed within days and fixed shortly after. Reputation damage from spam complaints, spam-trap hits or a burned domain takes longer, because rebuilding trust with mailbox providers is gradual and measured in weeks. Some fixes are process improvements on your side - how you collect consent, segment and send - which we recommend and help you implement, so that part of the timeline is a shared effort. We give you a realistic timeline after the audit and prioritise what moves the needle first.

Ask how they diagnose (do they run real authentication, reputation and placement checks, or just read your DNS?), whether they are ESP- and platform-agnostic or tied to one tool, what a typical engagement and timeline looks like, how they measure success (inbox placement and engagement, not vanity metrics), and whether they implement the fixes or just hand you a report. At Postbox Consultancy Services we are tool-agnostic, do the hands-on implementation, and report on real inbox performance.

Yes, and it needs attention quickly. Google's 2024 sender rules require bulk senders to stay under 0.3 percent (and ideally below 0.1 percent); above that, Gmail routes more of your mail to spam. We audit your program against Postmaster data and cut the complaint drivers - tighter segmentation so people only get relevant mail, sunsetting unengaged contacts, and a reengagement campaign to win back or drop dormant subscribers - alongside fixing any opt-in, one-click unsubscribe or authentication gaps, so the rate falls back under the threshold.

This is a common, diagnosable split. Microsoft weighs sender reputation (SNDS), IP history and its own filtering differently from Gmail, so mail Gmail trusts can still hit Outlook junk - often due to IP reputation, weak authentication alignment, low Microsoft-side engagement, or a SmartScreen history. We diagnose the Microsoft-specific signals, check your SNDS and JMRP status, fix the authentication and reputation gaps, and work your Outlook placement back up.

Barracuda (BRBL) is a blocklist real inboxes act on, so a listing needs prompt action. First confirm the listing and the reason - usually a spam-complaint spike, a compromised or misconfigured sender, or a shared-IP neighbour problem. Fix the root cause before requesting removal, then submit Barracuda's delisting request; removal is typically quick once the cause is resolved. We handle the diagnosis, the cleanup and the request, and check you are not listed elsewhere.

A sudden reply-rate drop is very often deliverability - if more of your mail is silently going to spam, replies fall even though your copy has not changed. It can also be domain reputation damage, a broken authentication change, or a blacklist listing. The way to confirm is a placement and reputation check: where is your mail actually landing, and did anything shift in your DNS, IPs or complaint rate. We diagnose it quickly and tell you plainly whether it is deliverability or something else.