Best AI Email Assistant for Thunderbird Alternatives in 2026
The top AI Email Assistant for Thunderbird alternatives are WPS AI Email Writer, MailMaestro and Lavender: 15 AI email writing tools our editors would look at instead of AI Email Assistant for Thunderbird, in our ranking order.
AI Email Assistant for Thunderbird: A free Thunderbird add-on for drafting, replying to and rewriting email with AI. Where it falls short: works with mozilla thunderbird, not gmail or outlook.
Switching from AI Email Assistant for Thunderbird? For most ai email writing tools buyers the best AI Email Assistant for Thunderbird alternative is WPS AI Email Writer, built for free, broad-platform prompt-based drafting. On a budget, Professionally AI Email Writer starts at $5.40/seat/mo. Kerna offers the most supported languages (45 languages).
Why People Look for an AI Email Assistant for Thunderbird Alternative
- Works with Mozilla Thunderbird, not Gmail or Outlook
- Focused on email writing rather than a broader toolset
- Community support may not suit buyers seeking other support channels
- No browser extension — 6 of the alternatives below have it
Quick Picks by What You Need
- Best overallWPS AI Email Writer9.1
Free, broad-platform prompt-based drafting
Visit WPS AI Email Writer - Lowest priceProfessionally AI Email Writer7.2
Paid plans from $5.40/seat/mo
Visit Professionally AI Email Writer - Best free optionWPS AI Email Writer9.1
Has a free plan
Visit WPS AI Email Writer - Most supported languagesKerna7.8
45 languages
Visit Kerna - Best for browser extensionForthWrite7.9
Browser extension (AI Email Assistant for Thunderbird: no)
Visit ForthWrite
All 15 AI Email Assistant for Thunderbird Alternatives, Ranked
Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.
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Best forFree, broad-platform prompt-based drafting
- Better than AI Email Assistant for Thunderbird:
- Editor score 9.1 vs 6.0
A free, unlimited prompt-based drafter for common email messages across six platforms.
9.1/10★★★★★Visit WPS -
Best forGmail and Outlook inbox productivity
- Better than AI Email Assistant for Thunderbird:
- Editor score 8.8 vs 6.0
A practical AI assistant for writing, organizing, and following up across Gmail and Outlook.
8.8/10★★★★☆Visit MailMaestro -
Best forSales teams optimizing outbound email quality
- Better than AI Email Assistant for Thunderbird:
- Editor score 8.5 vs 6.0
A sales-focused email coach with drafting, scoring, personalization, and team coaching.
8.5/10★★★★☆Visit Lavender -
Best forLarge teams needing governed email drafting
- Better than AI Email Assistant for Thunderbird:
- Editor score 8.3 vs 6.0
A governed email drafter with strong context controls, but paid plans start at $99 per user monthly.
- Custom instructions
- Tone controls
8.3/10★★★★☆Visit Workforce AI -
Best forTeams needing personalized email automation
- Better than AI Email Assistant for Thunderbird:
- Browser extension
- Editor score 7.9 vs 6.0
A thread-aware email assistant for personalized drafting and team workflows.
- Custom instructions
- Browser extension
- Tone controls
7.9/10★★★★☆Visit ForthWrite -
Best forMultilingual email and inbox workflows
- Better than AI Email Assistant for Thunderbird:
- Editor score 7.8 vs 6.0
A broad email workflow assistant for multilingual drafting, triage and extraction.
- Custom instructions
- Tone controls
7.8/10★★★★☆Visit Kerna -
Best forMac users needing connected email assistance
- Better than AI Email Assistant for Thunderbird:
- Editor score 7.7 vs 6.0
A connected Mac email assistant for drafting, triage, scheduling, and context retrieval.
7.7/10★★★★☆Visit Demi -
Best forBroad email writing at a low price
- Better than AI Email Assistant for Thunderbird:
- Browser extension
- Editor score 7.6 vs 6.0
Broad email drafting and reply support with a free plan and paid options from $5 per month annually.
- Browser extension
- Tone controls
7.6/10★★★★☆Visit WriteMail.ai -
Best forGmail users wanting research and writing tools
- Better than AI Email Assistant for Thunderbird:
- Browser extension
- Editor score 7.5 vs 6.0
A broad Gmail-focused writing assistant with research tools and a free plan.
- Custom instructions
- Browser extension
- Tone controls
7.5/10★★★★☆Visit Jetwriter AI -
Best forUsers wanting learned voice and inbox automation
- Better than AI Email Assistant for Thunderbird:
- Browser extension
- Editor score 7.4 vs 6.0
A strong fit for voice-trained drafting and inbox automation across Gmail and Outlook.
- Custom instructions
- Browser extension
- Tone controls
7.4/10★★★★☆Visit Ellie -
Best forGmail users wanting a focused writing assistant
- Better than AI Email Assistant for Thunderbird:
- Browser extension
- Editor score 7.3 vs 6.0
A focused Gmail writing assistant with broad drafting tools and Google-only compatibility.
- Browser extension
- Tone controls
7.3/10★★★★☆Visit GPT for Gmail -
Best forBudget-conscious Gmail and Outlook users
- Better than AI Email Assistant for Thunderbird:
- Browser extension
- Editor score 7.2 vs 6.0
A focused AI email assistant for Gmail and Outlook users who want flexible rewriting tools.
- Custom instructions
- Browser extension
- Tone controls
7.2/10★★★★☆Visit Professionally -
Best forGmail and Outlook users needing flexible replies
- Better than AI Email Assistant for Thunderbird:
- Editor score 7.1 vs 6.0
A flexible email assistant for drafting, replying, and expanding AI workflows.
7.1/10★★★★☆Visit Remail -
Best forOutbound teams personalizing prospect emails
- Better than AI Email Assistant for Thunderbird:
- Editor score 7.0 vs 6.0
A focused cold-email tool for personalized outbound at scale.
- Custom instructions
- Tone controls
7.0/10★★★★☆Visit Flailo -
Best forTechnical teams wanting self-hosted Gmail drafting
- Better than AI Email Assistant for Thunderbird:
- Editor score 6.9 vs 6.0
A free, self-hosted Gmail drafting tool for technical teams that want control over email data.
6.9/10★★★☆☆Visit Maillifier
AI Email Assistant for Thunderbird Alternatives: Common Questions
What is the best alternative to AI Email Assistant for Thunderbird?
WPS AI Email Writer: #1 in our AI Email Writing Tools ranking, with an editor score of 9.1 out of 10. A free, unlimited prompt-based drafter for common email messages across six platforms.
Is there a free alternative to AI Email Assistant for Thunderbird?
Yes. WPS AI Email Writer, MailMaestro, Lavender, Workforce AI Email Drafter and ForthWrite have a free plan or a free tier (13 of the 15 alternatives on this page).
What is the cheapest paid alternative to AI Email Assistant for Thunderbird?
Of the alternatives here that publish a price, Professionally AI Email Writer starts lowest, at $5.40/seat/mo.
Why do people look for AI Email Assistant for Thunderbird alternatives?
Works with Mozilla Thunderbird, not Gmail or Outlook; Focused on email writing rather than a broader toolset; Community support may not suit buyers seeking other support channels.
Which AI Email Assistant for Thunderbird alternative has the most supported languages?
Kerna, with 45 languages.
How do I switch from AI Email Assistant for Thunderbird?
Export your data from AI Email Assistant for Thunderbird (most tools have an export in their settings). Sign up for the alternative; start on its free plan or trial if it has one. Import your export and set up the integrations your team relies on. Run both side by side for a short while, then cancel AI Email Assistant for Thunderbird.
How to Switch from AI Email Assistant for Thunderbird
- Export your data from AI Email Assistant for Thunderbird (most tools have an export in their settings).
- Sign up for the alternative; start on its free plan or trial if it has one.
- Import your export and set up the integrations your team relies on.
- Run both side by side for a short while, then cancel AI Email Assistant for Thunderbird.
AI Email Assistant for Thunderbird vs Each Alternative
| # | Tool | Free plan | Paid from | Tone controls | Email context input | Browser extension | Mail client support | Score |
|---|---|---|---|---|---|---|---|---|
| 28 | AI Email Assistant for Thunderbird | Yes | Free | No | 6.0 | |||
| 1 | WPS AI Email Writer | Yes | Prompt | Both | 9.1 | |||
| 2 | MailMaestro | Yes | $12/seat/mo | 8.8 | ||||
| 3 | Lavender | Yes | $27/user/mo | 8.5 | ||||
| 4 | Workforce AI Email Drafter | Yes | $99/user/mo | Yes | Thread | Both | 8.3 | |
| 5 | ForthWrite | Yes | Yes | Thread | Yes | Both | 7.9 | |
| 6 | Kerna | Yes | €12/mo | Yes | Thread | No | Both | 7.8 |
| 7 | Demi | Yes | $25/mo | Thread | Both | 7.7 | ||
| 8 | WriteMail.ai | Yes | $60/yr | Yes | Thread | Yes | Both | 7.6 |
| 9 | Jetwriter AI | Yes | $14/mo | Yes | Inbox | Yes | Both | 7.5 |
| 10 | Ellie | Yes | Yes | Inbox | Yes | Both | 7.4 | |
| 11 | GPT for Gmail | Yes | $9/mo | Yes | Thread | Yes | Gmail | 7.3 |
| 12 | Professionally AI Email Writer | No | $5.40/seat/mo | Yes | Thread | Yes | Both | 7.2 |
| 13 | Remail | No | $9/user/mo | 7.1 | ||||
| 14 | Flailo | Yes | Yes | Both | 7.0 | |||
| 15 | Maillifier | Yes | Free | 6.9 |
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Last updated · How we research and update