Supported Protocols
Krantz Mail supports multiple email protocols to maximize compatibility across providers. Protocols are selected automatically based on the email domain.
Protocol Categories
Standard Protocols (Stable)
These protocols rely on open internet standards and will always be supported. They are the backbone of Krantz Mail.
| Protocol | Standard | Ports | Status |
|---|---|---|---|
| IMAP | RFC 3501 | 993 / 143 | Stable — always supported |
| POP3 | RFC 1939 | 995 | Stable — always supported |
| SMTP | RFC 5321 | 587 / 465 | Stable — always supported |
Standard protocols work with virtually every email provider — Gmail, Yahoo, AOL, Zoho, corporate mail, custom domains, and thousands more.
Webmail Protocols (Provider-Specific)
These protocols connect through provider-specific web interfaces instead of standard IMAP/POP3. They offer better success rates for their target providers but depend on the provider’s internal API.
| Protocol | Provider | Domains | Plan |
|---|---|---|---|
| Outlook | Microsoft | hotmail., outlook., live.*, msn.com | Pro |
| ABV | ABV.bg | abv.bg, gbg.bg, gyuvetch.bg | Pro |
| GMX | GMX | gmx.com, gmx.net, gmx.de, gmx.at, gmx.ch | Pro |
Important: Webmail protocols interact with provider-specific web interfaces that may change without notice. If a provider updates their login flow, security measures, or API structure, the corresponding protocol may temporarily stop working until we release an update. Standard protocols (IMAP, POP3, SMTP) are not affected by this and will continue working regardless.
Automatic Protocol Selection
You do not need to manually choose a protocol. Krantz Mail detects the email domain and routes it through the best available protocol:
- Microsoft domains → Outlook protocol (if Pro plan + enabled), otherwise IMAP
- ABV domains → ABV web protocol
- GMX domains → GMX web protocol
- All other domains → IMAP (primary), POP3 (fallback)
Feature Comparison
| Feature | IMAP | POP3 | SMTP | Outlook | ABV | GMX |
|---|---|---|---|---|---|---|
| Credential check | Yes | Yes | Yes | Yes | Yes | Yes |
| Mail viewer | Yes | — | — | Yes | — | — |
| Inbox search | Yes | — | — | Yes | Yes | Yes |
| Profile extraction | — | — | — | Pro | — | — |
| Folder access | Yes | — | — | Yes | — | — |
Protocol Stability
Will always work:
- IMAP, POP3, and SMTP are open standards. As long as an email provider supports them, Krantz Mail will work. These protocols have been stable for decades and will not break.
May require updates:
- Outlook, ABV, and GMX protocols reverse-engineer provider web interfaces. Providers can change their login flows, add new captcha challenges, or modify API endpoints at any time. When this happens, the affected protocol will stop working until we push a compatibility update. In the meantime, affected domains will automatically fall back to IMAP where possible.
We actively monitor all webmail protocols and release fixes as quickly as possible, but temporary disruptions are unavoidable with this approach.