Control panel features that may vary by hosting plan

Control panels are configured differently depending on the server, hosting plan, and location. A feature documented in official cPanel or aaPanel guides may work differently-or not be available at all-on your specific server. This article explains common areas where variations occur.

PHP versions and extensions

Available PHP versions depend on what the server administrator (UnderHost) has installed. Not every PHP version from 5.6 to 8.3 is necessarily available on every server. The MultiPHP dropdown in cPanel only shows what is installed on your server.

PHP extensions (GD, Imagick, Redis, Intl, etc.) are enabled per-server. If an extension is not listed in the MultiPHP INI Editor, it is not installed on that server. Contact support if you need an extension that is not available.

Email features

Full email hosting (SMTP, IMAP, spam filtering, DKIM signing) is available on shared cPanel and DirectAdmin plans. On CloudPanel and aaPanel VPS plans, email server configuration is significantly more involved and may not be pre-configured.

Port 25 (outgoing SMTP) is blocked by default on most shared hosting and many VPS plans for spam prevention. Transactional email (such as form notifications or WordPress emails) should be sent via an SMTP relay or third-party mail service rather than relying on port 25 directly. See Port 25 and SMTP policy.

SSL and HTTPS

AutoSSL (cPanel) and Let's Encrypt (DirectAdmin, CloudPanel, aaPanel) issue free SSL certificates automatically. However, SSL issuance will fail if:

• The domain DNS is not pointed to the server (A record must resolve to the server IP before SSL can be issued)
• Cloudflare or another proxy is intercepting the domain validation request (depends on proxy mode)
• The domain is on a subdomain with a wildcard DNS setup that does not validate correctly
• The CAA record on the domain restricts which CAs can issue for it

Backups

Backup availability and retention vary by plan:

• Some shared hosting plans include automated daily backups managed by UnderHost-see your plan details
• On plans without automated backups, you must create backups manually via the control panel
• VPS plans may include or exclude backup storage depending on the VPS product
• Control panel backup tools (cPanel Backup Wizard, DirectAdmin Backup, aaPanel backup) only back up what the panel can see-they do not replace a server-level backup strategy

Software installers

Softaculous (available in cPanel and some DirectAdmin plans) provides one-click WordPress and application installs. Softaculous is a licensed add-on; it is included on plans where UnderHost has purchased the licence. If your cPanel does not show Softaculous, it may not be included on your plan-ask support.

On CloudPanel and aaPanel, WordPress deployment is done differently-CloudPanel has a built-in WordPress installer, and aaPanel has an app store-but neither is identical to Softaculous.

CloudLinux resource limits (shared hosting)

UnderHost shared hosting servers run CloudLinux OS, which isolates accounts and enforces per-account resource limits. These limits (CPU usage, RAM, I/O, number of processes) are determined by your plan tier.

If your site hits these limits, you may see errors like:

• "508 Resource Limit Reached"
• "503 Service Unavailable"
• Slow page loads with no obvious cause

You can check your current resource usage in cPanel under Metrics → Resource Usage. See Understanding CloudLinux resource limits in cPanel for more detail.

VPS vs shared-key differences in the panel

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