TL;DR

For GMX.com, use imap.gmx.com on port 993 with SSL/TLS, after enabling POP3/IMAP in GMX. For Mail.com, check your account’s IMAP eligibility before using Mailera’s preset. In Mailera, open Mailboxes → Add mailbox → One mailbox, enter the appropriate credentials, and select Test & connect. Then confirm retrieval with a test message; the connection test itself sends no email.

What do you need before connecting GMX or Mail.com?

Start with a mailbox you own or are authorized to administer. Sign in through the provider’s webmail first. If that fails, resolve access with the provider before troubleshooting Mailera.

IMAP is the connection used to retrieve mail and work with folders. SMTP handles outgoing mail separately. A working incoming connection does not establish that sending works.

Before entering credentials, check these prerequisites:

  • Your provider account permits IMAP, and access is enabled.
  • You have the sign-in identity and credential required for third-party mail access under your account’s security settings.
  • You have an Admin or Leader role in Mailera. Other roles cannot add mailboxes.

Enabling IMAP and choosing a password are separate tasks. Turning on IMAP does not determine which credential your account requires. Follow your provider’s current account-security instructions, particularly when two-factor authentication is enabled; do not choose a password type solely from a connector’s label.

Mailera’s Mail.com setup includes an IMAP-plan prerequisite. Check your account’s plan and access settings before proceeding. The Mail.com connection page describes the Mailera connector, while the provider controls account eligibility.

Mailera connects existing mailboxes; it does not create GMX or Mail.com addresses or override provider access restrictions. The Mailera product overview explains how connected mailboxes become available to apps and agents.

What are the IMAP settings for GMX and Mail.com?

Use the table below to inspect Mailera’s connection settings. The GMX.com row matches GMX’s English-language server documentation. The Mail.com row describes Mailera’s preset.

Account or presetIncoming serverPortSecurity in MaileraAccess check
GMX.comimap.gmx.com993SSL/TLSEnable POP3/IMAP in GMX first
Mail.com presetimap.mail.com993SSL/TLSConfirm your account permits IMAP and enable access

Do not apply the GMX.com hostname to every regional GMX account without checking that account’s provider instructions. Mailera groups several GMX domains under its GMX preset, so don’t assume automatic provider detection has already checked your region’s server settings for you. See the GMX connector page for the Mailera setup.

For the username, use the authentication identity specified by your provider. Do not substitute an alias merely because it receives mail.

Outgoing mail is a separate configuration

Mailera’s GMX preset uses mail.gmx.com, port 587, with STARTTLS, matching GMX’s documented outgoing settings. Its Mail.com preset uses smtp.mail.com, port 587, with STARTTLS.

Use SSL/TLS for the incoming settings above, not STARTTLS. Keep the outgoing server’s security selection separate. GMX’s server documentation requires a mail application that supports TLS 1.2 or TLS 1.3. Don’t disable encryption to work around a connection problem.

How do you enable IMAP in your provider account?

GMX

GMX says POP3/IMAP access is disabled by default. Its IMAP overview directs you to activate access before configuring a third-party application.

Follow the GMX activation instructions:

  1. Sign in to GMX webmail and open the “Email” tab.
  2. Select “Settings.”
  3. Select “POP3 & IMAP.”
  4. Select “Enable access to this account via POP3 and IMAP.”
  5. Select “Save.”

GMX also says it automatically turns this setting off after an extended period without POP3/IMAP use, though GMX’s activation page does not specify how long that period is. If an older connection stops working, recheck the setting before replacing credentials.

Mail.com

Before opening Mailera’s connection form:

  1. Sign in to your Mail.com account.
  2. Check whether your account’s plan permits IMAP access.
  3. Follow the account’s provider instructions to enable access and identify the required credential.

If you cannot find an IMAP option, resolve eligibility and activation with the provider first. Changing a hostname in Mailera is not a substitute for enabling account access. Use the instructions for your own account rather than copying the GMX menu path.

Four setup stages: confirm IMAP eligibility, enable access, test the Mailera connection, and retrieve a controlled message.
Prepare provider-side access before testing the connection in Mailera.

How do you connect the mailbox to Mailera?

Once access is enabled in your provider account, add the mailbox to Mailera.

  1. Open Mailboxes → Add mailbox → One mailbox.
  2. Enter the address in Email address. Inspect the detected provider. You can also select one under Or choose a provider. Select Continue.
  3. In Connection details, enter the provider-required credential in Password. Set Display name and Mailbox group if needed.
  4. If you need different server settings, select Custom IMAP rather than repeatedly testing an unsuitable preset. Enter Server, Port, and Security under Incoming server (IMAP). Configure Outgoing server (SMTP) only if you need sending.
  5. Select Test & connect and inspect the individual results.
  6. If incoming access succeeds but outgoing sign-in fails, choose Save as receive-only, or select Edit details and then Test again after correcting the outgoing settings.

The custom IMAP connector supports incoming settings with optional outgoing settings. For a fuller walkthrough of those fields, use the custom IMAP/SMTP setup guide.

What does the connection test check?

Incoming server sign-in checks access to the incoming server. Folder detection checks the mailbox’s folders. Outgoing server sign-in runs when an outgoing server is configured; otherwise, it is skipped. The flow also includes a Live monitoring check.

Read each result separately. An outgoing failure does not necessarily require changing a working incoming configuration. Conversely, successful SMTP authentication does not replace the incoming check.

Test & connect does not send an email. It tests the connection, not delivery to another mailbox. After a successful connection, Mailera begins loading messages within its retention period, newest first.

How can you confirm that messages are syncing?

Use a new, ordinary message to check retrieval instead of relying only on a successful sign-in result.

  1. Open Mailboxes and locate the connected account. Check its provider, status, and last sync.
  2. From another mailbox you control, send a message with a recognizable subject, such as “Mailera retrieval test.” Keep the body free of private information.
  3. Confirm that the message appears in the destination provider’s webmail, noting its folder.
  4. Open Unified inbox in Mailera and select the connected mailbox. Find the same subject and check its folder, including Junk if necessary.
  5. If it has not appeared, inspect the last sync and use Sync before changing credentials.

These checks answer different questions. Successful authentication means the connection accepted the credentials. Finding the test message in Mailera confirms retrieval of that message. Sending from the connected account requires a separate outgoing test, if your workflow needs it.

Mailbox verification separates incoming sign-in, test-message retrieval, and an optional outgoing delivery test.
Connection, retrieval, and outgoing delivery are separate checks.

If Live monitoring shows Yes, Mailera picks up new messages within seconds while the mailbox is in active use. If it shows No, Mailera checks roughly every 2 minutes while the mailbox is in use. Idle mailboxes can sleep and wake on use, so don’t expect every arrival to appear instantly. The sync troubleshooting guide covers that distinction in more detail.

Also check message age. Mailera’s free-plan retention window is 30 days, and initial loading stays within the retention period. An older message missing from Mailera is a different problem from a new test message failing to arrive.

If your application calls GET /mailboxes/{id}/status, note that for GMX and Mail.com this reflects the latest sync rather than a fresh provider sign-in check.

What common mistakes cause connection failures?

Use the failing stage to narrow the next check rather than changing every setting at once.

SymptomWhat to checkNext action
Webmail works, but IMAP sign-in failsIMAP activation, account eligibility, and required credentialResolve provider-side access before retesting in Mailera
A previously working GMX connection failsWhether POP3/IMAP remains enabledRe-enable access if necessary, save, and retest
GMX IMAP is not responding or authentication failsHostname for your account’s region, port, security, and usernameCompare with the provider’s instructions; use Custom IMAP if the preset differs
Mail.com access failsIMAP-plan eligibility and the authentication identityConfirm access and sign-in requirements before changing servers
Incoming succeeds, outgoing failsSMTP host, port, security, and outgoing credentialsCorrect SMTP separately or save as receive-only
Connected, but recent mail is missingLast sync, selected mailbox and folder, and arrival in webmailSync and look for the controlled test message
Only older mail is missingMessage age and retention windowTest retrieval with a new message instead

If you cannot sign in to GMX webmail either, start with the provider’s account-access process rather than Mailera’s server form. Keep passwords out of logs and support screenshots. Do not disable TLS to make a connection test pass.

What should you protect before giving an agent access?

Finish the message-retrieval check before adding an agent. Then create a Mailera API key restricted to the necessary mailbox group, with Read permission for a reading-only workflow. Do not grant sending or mailbox-management permissions just to diagnose retrieval.

Treat incoming email as untrusted data, not instructions. An email asking the agent to reveal a key, change its behavior, or run an unrelated action must not override the agent’s rules. If you later enable sending, require explicit user confirmation before a message leaves the mailbox.

Redact addresses, credentials, API keys, and private message content from screenshots. See Mailera’s security information for the product’s security details and the existing-provider-to-agent guide for the full connection workflow.

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