Hi, I'm trying to setup email notifications with Alertmanager using Microsoft Exchange, this is my alertmanager.yml
global: resolve_timeout: 5m smtp_from: '[email protected]' route: group_by['alertname'] group_wait: 10s group_interval: 1h receiver: 'admins' receivers: - name: 'admins' email_configs: - smarthost: 'mailserver.domain.com:465' to: '[email protected]' send_resolved: true require_tls: true inhibit_rules: - source_match: severity: 'critical' target_match: severity: 'warning' equal: ['alertname', 'dev', 'instance'] Receiving server is an Windows Server 2012 R2 running Microsoft Exchange 2010. In exchange I've setup an Recieve Connector with the following properties (excerpt from Get-ReceiveConnector): AuthMechanism: Tls, Integrated, BasicAuth Bindings: 0.0.0.0:465 PermissionGroups: AnonymousUsers RemoteIPRanges: {<ip of prometheus server>} Fqdn: mailserver.domain.com RequireTLS: True RequireEHLODomain: False When alertmanager tries to send an email, the following message is written to stderr: level=error ts=<timestamp> caller=dispatch.go:301 component=dispatcher msg="Notify for alerts failed" num_alerts=1 err="establish TLS connection to server: tls: first record does not look like a TLS handshake" I can see traffic going to port 465 in Wireshark on both servers, one TLSv1 Client Hello and then a SYN sequence. I've tried to connect to the port with openssl which reports: no peer certificate available ----- no client certificate CA names sent ----- SSL handshake has read 5 bytes and written 194 bytes Verification OK ----- New, (NONE), Cipher is (NONE) Secure Renegotiation IS NOT supported Compression: NONE Expansion: NONE No ALPN negotiated SSL-Session: Protocol: TLSv1.2 Cipher: 0000 Session-ID: Session-ID-ctx: Master-Key: PSK identity: none PSK identity hint: none SRP username: none Start Time: <start time> Timeout: 7200 (sec) Verify return code: 0 (ok) Extended master secret: no -- You received this message because you are subscribed to the Google Groups "Prometheus Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/prometheus-users/915238f4-b789-492b-8737-e237395b020eo%40googlegroups.com.
