def get_comment_for_domain(domain):
    """Describe a domain name to produce a comment"""
    if domain.endswith((
            '.akamaiedge.net.',
            '.akamaized.net',
            '.edgekey.net.',
            '.static.akamaitechnologies.com.')):
        return 'Akamai CDN'
    if domain.endswith('.amazonaws.com.'):
        return 'Amazon AWS'
    if domain.endswith('.cdn.cloudflare.net.'):
        return 'Cloudflare CDN'
    if domain.endswith('.mail.gandi.net.') or domain == 'webmail.gandi.net.':
        return 'Gandi mail hosting'
    if domain == 'webredir.vip.gandi.net.':
        return 'Gandi web forwarding hosting'
    if domain == 'dkim.mcsv.net.':
        return 'Mailchimp mail sender'
    if domain.endswith('.azurewebsites.net.'):
        return 'Microsoft Azure hosting'
    if domain.endswith('.lync.com.'):
        return 'Microsoft Lync'
    if domain == 'clientconfig.microsoftonline-p.net.':
        # https://docs.microsoft.com/en-gb/office365/enterprise/external-domain-name-system-records
        return 'Microsoft Office 365 tenant'
    if domain.endswith(('.office.com.', '.office365.com.')):
        return 'Microsoft Office 365'
    if domain.endswith('.outlook.com.'):
        return 'Microsoft Outlook mail'
    if domain in ('redirect.ovh.net.', 'ssl0.ovh.net.'):
        return 'OVH mail provider'
    if domain.endswith('.hosting.ovh.net.'):
        return 'OVH shared web hosting'
    if domain.endswith('.rev.sfr.net.'):
        return 'SFR provider'
    return None