Cannot send and receive emails

[EleonoraEllington]

Hi! I have several emails on Roundcube and today all of them just stopped working. I cannot receive or send any emails. When I try to send them, I receive the following message immediately:
-------------------------
Mail delivery failed: returning message to sender

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

  "here was the recipient's email"@gmail.com
    host gmail-smtp-in.l.google.com [142.250.138.27]
    SMTP error from remote mail server after end of data:
    550-5.7.26 This mail has been blocked because the sender is unauthenticated.
    550-5.7.26 Gmail requires all senders to authenticate with either SPF or DKIM.
    550-5.7.26
    550-5.7.26  Authentication results:
    550-5.7.26  DKIM = did not pass
    550-5.7.26  SPF [lamarine-skincare.com] with ip:
    [104.225.208.26] = did not pass
    550-5.7.26
    550-5.7.26  To mitigate this issue, please visit Gmail's authentication guide
    550-5.7.26 for instructions on setting up authentication:
    550 5.7.26  https://support.google.com/mail/answer/81126#authentication x40-20020a056870332800b001d66918a314si1139039oae.2 - gsmtp
Reporting-MTA: dns; dfw-s04.nixihost.com

Action: failed
Final-Recipient: rfc822;"here was the recipient's email"@gmail.com
Status: 5.0.0
Remote-MTA: dns; gmail-smtp-in.l.google.com
Diagnostic-Code: smtp; 550-5.7.26 This mail has been blocked because the sender is unauthenticated.
550-5.7.26 Gmail requires all senders to authenticate with either SPF or DKIM.
550-5.7.26
550-5.7.26  Authentication results:
550-5.7.26  DKIM = did not pass
550-5.7.26  SPF [lamarine-skincare.com] with ip: [104.225.208.26] = did not pass
550-5.7.26
550-5.7.26  To mitigate this issue, please visit Gmail's authentication guide
550-5.7.26 for instructions on setting up authentication:
550 5.7.26  https://support.google.com/mail/answer/81126#authentication x40-20020a056870332800b001d66918a314si1139039oae.2 - gsmtp

When I send messages not to gmail (outlook, for instance) it says that the message is successfully sent, but the recipient gets nothing.

When I try to receive emails, nothing happens at all. Regardless of the sender (gmail, outlook, etc)

Could someone help me?

[JohnDoh]

Roundcube is a mail client. A free piece of software your email provider is using to give you webmail access. Your email providers mail server is responsible for sending/receiving email. Please contact your email provider for support.

[Dmitry42]

550-5.7.26 This mail has been blocked because the sender is unauthenticated.
    550-5.7.26 Gmail requires all senders to authenticate with either SPF or DKIM.
    550-5.7.26
    550-5.7.26  Authentication results:
    550-5.7.26  DKIM = did not pass
    550-5.7.26  SPF [lamarine-skincare.com] with ip:
    [104.225.208.26] = did not pass

You (or your internet server provider) must setup your DNS records ( SPF and DKIM records)