What are the top ISPs and mailbox providers in the UK?

Summary

Identifying the top ISPs and mailbox providers (MBPs) in the UK reveals a complex and nuanced landscape. While global webmail giants like Gmail, Outlook, and Yahoo dominate, there are significant shares held by broadband providers (BT, Virgin Media, Sky), mobile carriers, and regional ISPs (Plusnet, TalkTalk). Furthermore, the distinction between MBPs, ISPs, and filter providers (Mimecast, Proofpoint, Hornet) is blurring, with all acting as gatekeepers. The UK market also exhibits a trend towards specialized email hosting and security providers and niche providers catering to specific business needs. However, data regarding market share is often skewed based on methodologies and the inclusion of only .uk domains, with the major influencers using domain reputation to filter email. Therefore, optimizing email campaigns for major webmail platforms, adhering to data protection laws, and maintaining a positive sending domain reputation remain critical for email deliverability in the UK.

Key findings

  • Dominant Webmail Providers: Gmail, Outlook, and Yahoo are the major webmail providers in the UK.
  • Influence of Broadband Providers: BT, Virgin Media, and Sky serve as significant mailbox providers through bundled broadband services.
  • Filter Providers' Role: Mimecast, Proofpoint, and Hornet play a role as filter providers impacting deliverability.
  • Regional ISPs: Plusnet and TalkTalk operate as key regional ISPs.
  • Specialized Providers: A growing trend towards specialized email hosting and security providers exists.
  • Data Skew and Bias: Data on market share is often skewed depending on methodology and data sources.
  • Domain Reputation Matters: A strong sending domain reputation is critical for deliverability.
  • Mobile Carrier Impact: Mobile carriers' native email apps influence email access and usage.
  • Regulatory Compliance: Data protection and privacy laws influence how major ISPs and mailbox providers handle email data.

Key considerations

  • Optimize for Major Platforms: Ensure email campaigns are optimized for Gmail, Outlook, and Yahoo.
  • Monitor Sending Reputation: Proactively monitor and maintain a positive sending domain reputation.
  • Address Filter Providers: Understand and address the role of filter providers to ensure deliverability.
  • Comply with Data Protection Laws: Adhere to UK data protection and privacy laws when handling email data.
  • Account for Regional Variations: Account for variations in ISP usage across different regions of the UK.
  • Evaluate Specialized Providers: Evaluate the value and importance of specialized email hosting and security providers.
  • Acknowledge Data Limitations: Acknowledge the limitations and inherent biases in market share data.

What email marketers say
10Marketer opinions

Identifying the top ISPs and mailbox providers in the UK reveals a complex landscape. While global giants like Gmail, Outlook, Yahoo, and iCloud dominate, the market also includes significant shares held by broadband providers (BT, Sky, Virgin Media), mobile carriers, and regional ISPs (Plusnet, TalkTalk). Specialized email hosting and security providers, as well as smaller niche email providers, cater to specific business needs. The market is also influenced by the prevalence of filter providers and the trend towards specialized email hosting and security providers. Data regarding market share is often skewed depending on the methodologies used. Optimizing email campaigns for major webmail platforms remains crucial.

Key opinions

  • Dominant Providers: Gmail and Outlook are generally considered the dominant email providers in the UK.
  • Filter Providers: Entities like Mimecast, Proofpoint, and Hornet are significant filter providers.
  • Broadband Influence: Broadband providers (BT, Sky, Virgin Media) still offer email services, influencing usage patterns.
  • Mobile Impact: Mobile providers and their native email apps also affect email access and usage.
  • Regional Players: Regional ISPs (Plusnet, TalkTalk) are important in specific geographic areas.
  • Niche Providers: Smaller email providers cater to specialized business or privacy needs.
  • Data Skew: Data can be skewed depending on whether it includes only domains ending in .uk or includes actual ISP mailboxes
  • Email Security: Specialized email hosting and security providers are trending.

Key considerations

  • Platform Optimization: Optimize email campaigns for major webmail platforms (Gmail, Outlook, Yahoo).
  • Filter Awareness: Be aware of the role of filter providers in deliverability.
  • Regional Targeting: Consider regional variations in ISP usage.
  • Niche Targeting: If targeting specific industries, consider niche email providers.
  • Data Bias: Acknowledge that data on the market is biased depending on methodology.
Marketer view

Email marketer from Reddit shares that the major email providers in the UK include Gmail, Outlook, Yahoo, and iCloud, although the specific market share breakdown can fluctuate.

March 2022 - Reddit
Marketer view

Marketer from Email Geeks believes the data is skewed when looking for domains ending in .uk, and the list might not include many actual ISP mailboxes.

May 2023 - Email Geeks
Marketer view

Email marketer from Online Marketing Blog responds that broadband providers such as BT, Sky, and Virgin Media still offer email services to their customers, and this can influence email usage patterns across the UK.

November 2023 - Online Marketing Blog
Marketer view

Email marketer from EmailVendorSelection.com shares that there's a trend towards specialized email hosting and security providers alongside traditional ISPs. The UK market sees a mix of global players and niche providers catering to specific business needs.

March 2023 - EmailVendorSelection.com
Marketer view

Email marketer from Mobile Marketing Forum notes that mobile providers also affect email usage, with their native email apps facilitating access to various email accounts, which may vary depending on user preferences.

November 2023 - Mobile Marketing Forum
Marketer view

Email marketer from Digital Marketing Community highlights the pervasive use of webmail services like Gmail, Outlook, and Yahoo Mail in the UK, suggesting marketers should optimize campaigns for these platforms.

September 2024 - Digital Marketing Community
Marketer view

Email marketer from Email Marketing Forum responds that while specific numbers change, Gmail and Outlook are generally considered the dominant email providers in the UK, with Yahoo and smaller regional ISPs also holding significant shares.

September 2024 - Email Marketing Forum
Marketer view

Marketer from Email Geeks suggests that some entities on the list are better described as filter providers, such as Mimecast, Proofpoint, and Hornet.

January 2025 - Email Geeks
Marketer view

Email marketer from Local Business Forums UK explains that regional ISPs like Plusnet and TalkTalk also play a role, particularly in specific geographic areas. These providers often bundle email services with their internet packages.

January 2022 - Local Business Forums UK
Marketer view

Email marketer from Webmaster Forum responds that smaller email providers and hosting companies often cater to specific niches. These include companies offering privacy-focused email or specialized business solutions. It is hard to give a definitive list.

April 2022 - Webmaster Forum

What the experts say
5Expert opinions

Identifying top ISPs and mailbox providers (MBPs) in the UK is complex due to varying measurement methods and inherent biases in data. While external distinctions between MBPs, ISPs, and filter providers blur (all acting as "mx gatekeepers"), maintaining a good sending domain reputation remains critical for deliverability. Data from sources like Return Path/Validity and Litmus offers insights, though accuracy varies. Analyzing and acknowledging the limits of any data slicing and ranking methodology is essential.

Key opinions

  • Measurement Methods: Multiple ways exist to measure top ISPs/MBPs, each with limitations.
  • Blurred Lines: The distinction between MBPs, ISPs, and filter providers is often unclear externally; they are all 'mx gatekeepers'.
  • Data Bias: Data is inherently biased, regardless of analysis methods.
  • Data Sources: Return Path/Validity and Litmus data offer insights but have varying accuracy.
  • Reputation Importance: Good sending domain reputation is critical for deliverability at UK ISPs/MBPs.

Key considerations

  • Acknowledge Limitations: Acknowledge the limitations of any dataset or ranking methodology.
  • Analyze Data Critically: Critically analyze data sources and collection methods.
  • Manage Reputation: Prioritize maintaining a positive domain sending reputation.
  • Understand Gatekeepers: Recognize that multiple entities (MBPs, ISPs, filter providers) act as email gatekeepers.
  • Consult Multiple Sources: Consult and compare data from multiple sources for a more comprehensive view.
Expert view

Expert from Email Geeks says that externally the distinction between MBPs, ISPs, and Filterers blurs. They are all essentially "mx gatekeepers".

December 2023 - Email Geeks
Expert view

Expert from Word to the Wise explains that ISPs and mailbox providers in the UK, like those elsewhere, heavily rely on domain reputation to filter email. Maintaining a good sending reputation is critical for deliverability.

April 2021 - Word to the Wise
Expert view

Expert from Email Geeks acknowledges the data will be biased almost no matter how you slice it, so it is important to slice it, and note the limits of the slicing and ranking.

January 2025 - Email Geeks
Expert view

Expert from Email Geeks shares a snapshot view of top ISPs/MBPs in the UK, noting that there are multiple ways to measure this, each with its limitations. For more details and methodology, see: <https://www.spamresource.com/2022/12/fun-with-data-top-uk-mailbox-providers.html>

January 2025 - Email Geeks
Expert view

Expert from Spam Resource suggests that data from companies like Return Path (now Validity) and Litmus can provide insights into mailbox provider market share in the UK. However, the accuracy can vary based on data collection methods.

October 2023 - Spam Resource

What the documentation says
5Technical articles

Government and regulatory documentation provide indirect insights into the top ISPs and mailbox providers in the UK. Ofcom's Communications Market Report highlights the significance of broadband and mobile providers like BT, Virgin Media, and Sky. GOV.UK emphasizes secure and reliable internet services often bundled with email. ICO.org.uk underscores the reliance on major providers for email marketing compliance, linking it to data protection and consent. Nominet's data on .uk domain registrations hints at the role of local email providers. Finally, the Data Protection Act underscores the legal compliance requirements for ISPs and mailbox providers regarding personal data in emails.

Key findings

  • Broadband Dominance: BT, Virgin Media, and Sky are significant mailbox providers through their broadband services.
  • Webmail Reliance: There's an increasing reliance on webmail services from global tech companies.
  • Bundled Services: Email services are often bundled with secure and reliable internet services.
  • Compliance Imperative: Major ISPs and mailbox providers must comply with data protection regulations.
  • Local Domains: .uk domain registrations indicate the presence of local email providers.

Key considerations

  • Broadband Targeting: Consider broadband providers when targeting UK email users.
  • Compliance Adherence: Ensure email marketing campaigns comply with UK data protection laws.
  • Secure Services: Prioritize secure and reliable email delivery.
  • Local Integration: Consider the role of local email providers in specific regions.
  • Monitor Regulations: Stay updated on relevant regulations affecting ISPs and mailbox providers.
Technical article

Documentation from legislation.gov.uk explains Data Protection Act details data protection compliance, indirectly discussing how major ISPs and mailbox providers in the UK must comply with these regulations when handling personal data in emails.

September 2022 - legislation.gov.uk
Technical article

Documentation from GOV.UK provides information on the UK internet landscape, indirectly referencing major ISPs and their impact on email provision. It emphasizes the importance of secure and reliable internet services, which are often bundled with email services.

April 2023 - GOV.UK
Technical article

Documentation from ICO.org.uk provides guidance on email marketing compliance, indirectly referring to the reliance on major ISPs and mailbox providers for delivering marketing communications in the UK, highlighting the need for data protection and consent.

October 2022 - ICO.org.uk
Technical article

Documentation from Ofcom details the UK Communications Market Report which, while not explicitly listing email providers, offers insight into broadband and mobile usage, indirectly pointing to ISPs like BT, Virgin Media, and Sky as significant mailbox providers. The report highlights the competitive landscape and the increasing reliance on webmail services offered by global tech companies.

May 2023 - Ofcom
Technical article

Documentation from Nominet details domain name registration, and provides indirect insights into email usage by tracking domain registrations associated with email services. It shows the popularity of .uk domains, often linked to local email providers.

April 2024 - Nominet