| Yahoo / AOL |
Excessive advertising. AOL suffers from constant ownership shifts. Yahoo's business strategy is volatile (e.g., slashing storage from 1TB to 20GB). |
| Outlook |
Subpar spam filtering (flags its own internal mail). Frequent large-scale system outages. |
| GMX / Mail.com |
Overly aggressive risk control leads to arbitrary account deletions without clear reasons. |
| Zoho |
Feels more like a bloated CRM suite than a streamlined, pure email service. |
| Infomaniak |
Similar to Zoho; suffers from feature bloat and a lack of simplicity. |
| iCloud |
Persistent issues with "silent" email loss (messages disappearing without bounce-back). |
| Yandex |
Poor deliverability; many legitimate incoming messages are incorrectly flagged as spam. |
| Mail.ru |
Unreliable rejection of incoming mail; even technical mailing lists are frequently blocked. |
| ProtonMail |
Lacks standard IMAP support (requires a bridge). The webmail interface is notably sluggish. |
| Mailbox.org |
Cluttered and bloated User Interface (OX Webmail). Customer service is mediocre. |
| Posteo |
Lacks support for custom domains, which is a significant limitation for power users. |
| Runbox |
Poor webmail UX and an incredibly slow development/update cycle. |
| Codamail |
High-quality service overall, but the webmail interface performance is very slow. |
| Kolab Now |
Expensive pricing combined with occasional stability issues. |