diff --git a/dns/mock.go b/dns/mock.go
index 2a8e84b..b0d420c 100644
--- a/dns/mock.go
+++ b/dns/mock.go
@@ -44,6 +44,9 @@ func (r MockResolver) servfail(s string) *net.DNSError {
 }
 
 func (r MockResolver) LookupCNAME(ctx context.Context, name string) (string, error) {
+	if err := ctx.Err(); err != nil {
+		return "", err
+	}
 	if _, ok := r.Fail[Mockreq{"cname", name}]; ok {
 		return "", r.servfail(name)
 	}
@@ -54,6 +57,9 @@ func (r MockResolver) LookupCNAME(ctx context.Context, name string) (string, err
 }
 
 func (r MockResolver) LookupAddr(ctx context.Context, ip string) ([]string, error) {
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
 	if _, ok := r.Fail[Mockreq{"ptr", ip}]; ok {
 		return nil, r.servfail(ip)
 	}
@@ -65,18 +71,30 @@ func (r MockResolver) LookupAddr(ctx context.Context, ip string) ([]string, erro
 }
 
 func (r MockResolver) LookupNS(ctx context.Context, name string) ([]*net.NS, error) {
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
 	return nil, r.servfail("ns not implemented")
 }
 
 func (r MockResolver) LookupPort(ctx context.Context, network, service string) (port int, err error) {
+	if err := ctx.Err(); err != nil {
+		return 0, err
+	}
 	return 0, r.servfail("port not implemented")
 }
 
 func (r MockResolver) LookupSRV(ctx context.Context, service, proto, name string) (string, []*net.SRV, error) {
+	if err := ctx.Err(); err != nil {
+		return "", nil, err
+	}
 	return "", nil, r.servfail("srv not implemented")
 }
 
 func (r MockResolver) LookupIPAddr(ctx context.Context, host string) ([]net.IPAddr, error) {
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
 	if _, ok := r.Fail[Mockreq{"ipaddr", host}]; ok {
 		return nil, r.servfail(host)
 	}
@@ -96,6 +114,9 @@ func (r MockResolver) LookupIPAddr(ctx context.Context, host string) ([]net.IPAd
 }
 
 func (r MockResolver) LookupHost(ctx context.Context, host string) (addrs []string, err error) {
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
 	if _, ok := r.Fail[Mockreq{"host", host}]; ok {
 		return nil, r.servfail(host)
 	}
@@ -111,6 +132,9 @@ func (r MockResolver) LookupHost(ctx context.Context, host string) (addrs []stri
 }
 
 func (r MockResolver) LookupIP(ctx context.Context, network, host string) ([]net.IP, error) {
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
 	if _, ok := r.Fail[Mockreq{"ip", host}]; ok {
 		return nil, r.servfail(host)
 	}
@@ -134,6 +158,9 @@ func (r MockResolver) LookupIP(ctx context.Context, network, host string) ([]net
 }
 
 func (r MockResolver) LookupMX(ctx context.Context, name string) ([]*net.MX, error) {
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
 	if _, ok := r.Fail[Mockreq{"mx", name}]; ok {
 		return nil, r.servfail(name)
 	}
@@ -145,6 +172,9 @@ func (r MockResolver) LookupMX(ctx context.Context, name string) ([]*net.MX, err
 }
 
 func (r MockResolver) LookupTXT(ctx context.Context, name string) ([]string, error) {
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
 	if _, ok := r.Fail[Mockreq{"txt", name}]; ok {
 		return nil, r.servfail(name)
 	}
diff --git a/queue/queue.go b/queue/queue.go
index 0776f65..f345196 100644
--- a/queue/queue.go
+++ b/queue/queue.go
@@ -658,7 +658,10 @@ func gatherHosts(resolver dns.Resolver, m Msg, cid int64, qlog *mlog.Log) (hosts
 			}
 
 			// No MX record. First attempt CNAME lookup. ../rfc/5321:3838 ../rfc/3974:197
+			ctx, cancel = context.WithTimeout(cidctx, 30*time.Second)
+			defer cancel()
 			cname, err := resolver.LookupCNAME(ctx, effectiveDomain.ASCII+".")
+			cancel()
 			if err != nil && !dns.IsNotFound(err) {
 				return nil, effectiveDomain, false, fmt.Errorf("%w: cname lookup for %s: %v", errDNS, effectiveDomain, err)
 			}